Truth ignored by schools

Excellent article by Alfie Kohn that all educators should read.


“Well, Duh!” — Ten Obvious Truths That We Shouldn’t Be Ignoring
By Alfie Kohn

The field of education bubbles over with controversies. It’s not unusual for intelligent people of good will to disagree passionately about what should happen in schools. But there are certain precepts that aren’t debatable, that just about anyone would have to acknowledge are true.

While many such statements are banal, some are worth noticing because in our school practices and policies we tend to ignore the implications that follow from them. It’s both intellectually interesting and practically important to explore such contradictions: If we all agree that a given principle is true, then why in the world do our schools still function as if it weren’t?

Here are 10 examples.

1. Much of the material students are required to memorize is soon forgotten

The truth of this statement will be conceded (either willingly or reluctantly) by just about everyone who has spent time in school — in other words, all of us. A few months, or sometimes even just a few days, after having committed a list of facts, dates, or definitions to memory, we couldn’t recall most of them if our lives depended on it. Everyone knows this, yet a substantial part of schooling – particularly in the most traditional schools – continues to consist of stuffing facts into students’ short-term memories.

The more closely we inspect this model of teaching and testing, the more problematic it reveals itself to be. First, there’s the question of what students are made to learn, which often is more oriented to factual material than to a deep understanding of ideas. (See item 2, below.) Second, there’s the question of how students are taught, with a focus on passive absorption: listening to lectures, reading summaries in textbooks, and rehearsing material immediately before being required to cough it back up. Third, there’s the question of why a student has learned something: Knowledge is less likely to be retained if it has been acquired so that one will perform well on a test, as opposed to learning in the context of pursuing projects and solving problems that are personally meaningful.

Even without these layers of deficiencies with the status quo, and even if we grant that remembering some things can be useful, the fundamental question echoes like a shout down an endless school corridor: Why are kids still being forced to memorize so much stuff that we know they won’t remember?

Corollary 1A: Since this appears to be true for adults, too, why do most professional development events for teachers resemble the least impressive classrooms, with experts disgorging facts about how to educate?

2. Just knowing a lot of facts doesn’t mean you’re smart

Even students who do manage to remember some of the material they were taught are not necessarily able to make sense of those bits of knowledge, to understand connections among them, or to apply them in inventive and persuasive ways to real-life problems.

In fact, the cognitive scientist Lauren Resnick goes even further: It’s not just that knowing (or having been taught) facts doesn’t in itself make you smart. A mostly fact-oriented education may actually interfere with your becoming smart. “Thinking skills tend to be driven out of the curriculum by ever-growing demands for teaching larger and larger bodies of knowledge,” she writes. Yet schools continue to treat students as empty glasses into which information can be poured — and public officials continue to judge schools on the basis of how efficiently and determinedly they pour.

3. Students are more likely to learn what they find interesting

There’s no shortage of evidence for this claim if you really need it. One of many examples: A group of researchers found that children’s level of interest in a passage they were reading was 30 times more useful than its difficulty level for predicting how much of it they would later remember. But this should be obvious, if only because of what we know about ourselves. It’s the tasks that intrigue us, that tap our curiosity and connect to the things we care about, that we tend to keep doing — and get better at doing. So, too, for kids.

Conversely, students are less likely to benefit from doing what they hate. Psychology has come a long way from the days when theorists tried to reduce everything to simple stimulus-response pairings. We know now that people aren’t machines, such that an input (listening to a lecture, reading a textbook, filling out a worksheet) will reliably yield an output (learning). What matters is how people experience what they do, what meaning they ascribe to it, what their attitudes and goals are.

Thus, if students find an academic task stressful or boring, they’re far less likely to understand, or even remember, the content. And if they’re uninterested in a whole category of academic tasks — say, those they’re assigned to do when they get home after having just spent a whole day at school — then they aren’t likely to benefit much from doing them. No wonder research finds little, if any, advantage to assigning homework, particularly in elementary or middle school.

4. Students are less interested in whatever they’re forced to do and more enthusiastic when they have some say

Once again, studies confirm what we already know from experience. The nearly universal negative reaction to compulsion, like the positive response to choice, is a function of our psychological makeup.

Now combine this point with the preceding one: If choice is related to interest, and interest is related to achievement, then it’s not much of a stretch to suggest that the learning environments in which kids get to make decisions about what they’re doing are likely to be the most effective, all else being equal. Yet such learning environments continue to be vastly outnumbered by those where kids spend most of their time just following directions.

5. Just because doing x raises standardized test scores doesn’t mean x should be done

At the very least, we would need evidence that the test in question is a source of useful information about whether our teaching and learning goals are being met. Many educators have argued that the tests being used in our schools are unsatisfactory for several reasons.

First, there are numerous limitations with specific tests. Second, most tests share certain problematic features, such as being timed (which places more of a premium on speed than on thoughtfulness), norm-referenced (which means the tests are designed to tell us who’s beating whom, not how well students have learned or teachers have taught), and consisting largely of multiple-choice questions (which don’t permit students to generate or even explain their answers).

The third reason is the problems inherent to all tests that are standardized and created by people far away from the classroom — as opposed to assessing the actual learning taking place there on an on-going basis.

This is not the place to explain in detail why standardized tests measure what matters least. Here, I want only to make the simpler — and, once again, I think, indisputable — point that anyone who regards high or rising test scores as good news has an obligation to show that the tests themselves are good. If a test result can’t be convincingly shown to be both valid and meaningful, then whatever we did to achieve that result — say, a new curriculum or instructional strategy — may well have no merit whatsoever. It may even prove to be destructive when assessed by better criteria. Indeed, a school or district might be getting worse even as its test scores rise.

So how is it that articles in newspapers and education journals, as well as pronouncements by public officials and think tanks, seem to accept on faith that better scores on any test necessarily constitute good news, and that whatever produced those scores can be described as “effective”? Parents should be encouraged to ask, “How much time was sacrificed from real learning just so our kids could get better at taking the [name of test]?”

6. Students are more likely to succeed in a place where they feel known and cared about

I realize there are people whose impulse is to sneer when talk turns to how kids feel, and who dismiss as “soft” or “faddish” anything other than old-fashioned instruction of academic skills. But even these hard-liners, when pressed, are unable to deny the relationship between feeling and thinking, between a child’s comfort level and his or her capacity to learn.

Here, too, there are loads of supporting data. As one group of researchers put it, “In order to promote students’ academic performance in the classroom, educators should also promote their social and emotional adjustment.” And yet, broadly speaking, we don’t. Teachers and schools are evaluated almost exclusively on academic achievement measures (which, to make matters worse, mostly consist of standardized test scores).

If we took seriously the need for kids to feel known and cared about, our discussions about the distinguishing features of a “good school” would sound very different. Likewise, our view of discipline and classroom management would be turned inside-out, seeing as how the primary goals of most such strategies are obedience and order, often with the result that kids feel less cared about — or even bullied — by adults.

7. We want children to develop in many ways, not just academically

Even mainstream education groups have embraced the idea of teaching the “whole child.” It’s a safe position, really, because just about every parent or educator will tell you that we should be supporting children’s physical, emotional, social, moral, and artistic growth as well as their intellectual growth. Moreover, it’s obvious to most people that the schools can and should play a key role in promoting many different forms of development.

If we acknowledge that academics is just one facet of a good education, why do so few conversations about improving our schools deal with — and why are so few resources devoted to — non-academic issues? And why do we assign children still more academic tasks after the school day is over, even when those tasks cut into the time children have to pursue interests that will help them develop in other ways?

Corollary 7a: Students “learn best when they are happy,” as educator Nel Noddings reminded us, but that doesn’t mean they’re especially likely to be happy (or psychologically healthy) just because they’re academically successful. And millions aren’t. Imagine how high schools would have to be changed if we were to take this realization seriously.

8. Just because a lesson (or book, or class, or test) is harder doesn’t mean it’s better

First, if it’s pointless to give students things to do that are too easy, it’s also counterproductive to give them things that they experience as too hard. Second, and more important, this criterion overlooks a variety of considerations other than difficulty level by which educational quality might be evaluated.

We know this, yet we continue to worship at the altar of “rigor.” I’ve seen lessons that aren’t unduly challenging yet are deeply engaging and intellectually valuable. Conversely, I’ve seen courses — and whole schools — that are indisputably rigorous . . . and appallingly bad.

9. Kids aren’t just short adults

Over the past hundred years, developmental psychologists have labored to describe what makes children distinctive and what they can understand at certain ages. There are limits, after all, to what even a precocious younger child can grasp (e.g., the way metaphors function, the significance of making a promise) or do (e.g., keep still for an extended period).

Likewise, there are certain things children require for optimal development, including opportunities to play and explore, alone and with others. Research fills in — and keeps fine-tuning — the details, but the fundamental implication isn’t hard to grasp: How we educate kids should follow from what defines them as kids.

Somehow, though, developmentally inappropriate education has become the norm, as kindergarten (literally, the “children’s garden”) now tends to resemble a first- or second-grade classroom — in fact, a bad first- or second-grade classroom, where discovery, creativity, and social interaction are replaced by a repetitive regimen focused on narrowly defined academic skills.

More generally, premature exposure to sit-still-and-listen instruction, homework, grades, tests, and competition — practices that are clearly a bad match for younger children and of questionable value at any age — is rationalized by invoking a notion I’ve called BGUTI: Better Get Used To It. The logic here is that we have to prepare you for the bad things that are going to be done to you later . . . by doing them to you now. When articulated explicitly, that principle sounds exactly as ridiculous as it is. Nevertheless, it’s the engine that continues to drive an awful lot of nonsense.

The obvious premise that we should respect what makes children children can be amended to include a related principle that is less obvious to some people: Learning something earlier isn’t necessarily better. Deborah Meier, whose experience as a celebrated educator ranges from kindergarten to high school, put it bluntly: “The earlier [that schools try] to inculcate so-called ‘academic’ skills, the deeper the damage and the more permanent the ‘achievement’ gap.” That is exactly what a passel of ambitious research projects has found: A traditional skills-based approach to teaching young children — particularly those from low-income families — not only offers no lasting benefits but appears to be harmful.

Corollary 9A: Kids aren’t just future adults. They are that, of course, but they aren’t only that, because children’s needs and perspectives are worth attending to in their own right. We violate this precept — and do a disservice to children — whenever we talk about schooling in economic terms, treating students mostly as future employees.

10. Substance matters more than labels

A skunk cabbage by any other name would smell just as putrid. But in education, as in other domains, we’re often seduced by appealing names when we should be demanding to know exactly what lies behind them. Most of us, for example, favor a sense of community, prefer that a job be done by professionals, and want to promote learning. So should we sign on to the work being done in the name of “Professional Learning Communities”? Not if it turns out that PLCs have less to do with helping children to think deeply about questions that matter than with boosting standardized test scores.

The same caution is appropriate when it comes to “Positive Behavior Support,” a jaunty moniker for a program of crude Skinnerian manipulation in which students are essentially bribed to do whatever they’re told. More broadly, even the label “school reform” doesn’t necessarily signify improvement; these days, it’s more likely to mean “something that skillful and caring teachers wouldn’t be inclined to do unless coerced,” as educational psychologist Bruce Marlowe put it.

In fact, the corporate-style version of “school reform” that’s uncritically endorsed these days by politicians, journalists, and billionaires consists of a series of debatable tactics — many of them amounting to bribes and threats to force educators to jack up test scores. Just as worrisome, though, is that these reformers often overlook, or simply violate, a number of propositions that aren’t debatable, including many of those listed here.


This essay is an abridged version of the introduction to Feel-Bad Education…And Other Contrarian Essays on Children and Schooling (Beacon Press, 2011)

Copyright © 2011 by Alfie Kohn. This article may be downloaded, reproduced, and distributed without permission as long as each copy includes this notice along with citation information (i.e., name of the periodical in which it originally appeared, date of publication, and author’s name). Permission must be obtained in order to reprint this article in a published work or in order to offer it for sale in any form. We can be reached through the Contact Us page. — © Alfie Kohn

vocabulary for kids

Those interested in making sure kindergarten children learn lots of “academic” or “really big” words (“San Lorenzo kindergartners make big strides in mastering language,” InsideBayArea news, Dec. 8) might want to read a recent study done by Alice Sullivan and Matt Brown of the Centre for Longitudinal Studies in London. The study shows that having a large vocabulary at age five has only a small relationship with having a large vocabulary when you are an adult. In contrast, Sullivan and Brown reported the amount of reading we do as adults has a strong relationship to adult vocabulary size.
This is in agreement with many studies that show that we gradually acquire the meaning of complex words as we see them in print in a comprehensible context.
Developing a love of reading through stories and strengthening libraries might be a better investment than giving five-year-olds vocabulary lessons.

source Krashen

Natural language learning

From Steve Kaufmann;


Here are seven concepts of natural language learning that reflect the most recent research on how the brain learns.

1. The brain can learn languages, trust it.

The brain learns all the time, and, in fact, is designed to learn. Throughout our lives the brain retains “plasticity”, creating neurons, and neural connections, in response to what it sees, hears and experiences. The brain draws its own conclusions from the input it receives, and is better at forming its own rules than understanding logical explanations. The brain is always at work, consuming over 20% of the body’s calories. We can learn languages right into old age, and in fact it is good for the brain to do so.

The brain develops its own rules, naturally, from the observation of the input it receives.
The brain takes its time to learn, requiring continued exposure to meaningful and interesting content.
The brain can prioritize what to learn, dealing with easier subjects first, and more difficult ones later.
2. The brain needs stimulus. Give it massive amounts of meaningful input.

The brain likes things that are relevant and interesting. So if the task is language acquisition, the most important condition is massive and continuous exposure to interesting and relevant language content. At first, when the language is new, it is helpful to reinforce what has been learned by repetitive listening and reading. As we progress we need to find new, fresh, interesting, stimulating and meaningful content.

We learn better from stories, real conversations, examples and episodes than from rules and facts.
We learn best from content that matters to us.
It is easier to listen to and read content is at the right level of difficulty, however the interest and relevance to the learner is the most important consideration.
3. The brain will miss things. We can help the brain notice the language.

The brain learns naturally by observing, constantly labeling and creating its own rules. But the brain can miss things. We should, from time to time, review grammar rules and tables, focus on mistakes we have made, or study specific words and phrases that we have learned. We should also attempt to write and speak, if we feel like it. These activities, which dominate traditional language learning, are, however, optional and minor activities in a natural language learning system. They increase attentiveness but should not take away from the main activities of listening and reading.

Good language output can only come from absorbing massive amounts of language input.
When we practice output, speaking and writing, or review vocabulary and grammar rules, we increase our attentiveness to the language.
Heightened attentiveness increases the ability of the brain to notice the patterns and sounds of the language.
4. Learn to engage your emotions in order to increase learning efficiency.

Positive emotions energize the brain, and increase the efficiency of learning. An interesting story, a powerfully narrated audio book, a person we like – these are the things that will engage our emotions. Uninteresting learning tasks, or negative tension, decrease learning efficiency.

We should stay with content we like, and discard content we do not like. We should do those learning tasks we enjoy doing.
We should always combine audio with text, and choose narrators whose voice we enjoy. This will make it easier to listen repetitively.
We need to like the language we are learning and at least some aspects of its culture.
5. When you learn naturally, you will feel motivated by your own success.

Motivation is the basic motor of learning. Success is motivating, as is praise. Any teaching activity which creates frustration, such as traditional grammar based language learning, can demotivate the learner. In a natural learning environment, the main task of the teacher is to encourage the learner to become independent of the teacher, rather than to impose tasks or explanations on the learner.

Many of us want to learn another language but are skeptical of our ability to do so, because we have not done it before.
As the strange language starts to acquire meaning through our listening and reading, our brain feels a sense of reward at this new and unexpected experience. This is highly motivating.
Give language learning a chance, the results will be better than you think.
6. When we learn, we change. We need to accept this change.

When we learn, our neural networks change, physically. When we learn a new language, we adopt some of the behaviour patterns of another culture and our personalities and our perceptions change. Many of the difficulties that grown-ups face in language learning, come from the a resistance to change. It is often more comfortable to follow the patterns and pronunciation of our own language, rather than to commit to fully imitating the new language.

Children are not afraid to change. Moving to a new country, they learn the language of their new friends without hesitation.
Older learners have a stronger vested interested in their own identity, and in what they already know.
All learners benefit from the help of an encouraging tutor and an enthusiastic group of fellow learners, in order to overcome these barriers to learning.
7. The Internet – the new world of natural learning at our finger-tips.

The internet offers a wide range of content in many languages, many low-cost websites with efficient learning methodologies, online tutors, and people from around the world with whom to talk and interact. The internet becomes the classroom, the library, the source of content, the language laboratory, and the support community. The Internet is the home of the language learning revolution, the natural language learning revolution.

Internet learning is available whenever we want, at no, or little, cost.
The iPod or MP3 player and other language resources on the Web have created a natural language learning revolution.
Join a language learning community on the Web today!


How to learn a new language: 7 secrets from TED Translators

From the good people at TED;


By Krystian Aparta
They say that children learn languages the best. But that doesn’t mean that adults should give up. We asked some of the polyglots in TED’s Open Translation Project to share their secrets to mastering a foreign language. Their best strategies distill into seven basic principles:

Get real. Decide on a simple, attainable goal to start with so that you don’t feel overwhelmed. German translator Judith Matz suggests: “Pick up 50 words of a language and start using them on people — and then slowly start picking up grammar.”
Make language-learning a lifestyle change. Elisabeth Buffard, who in her 27 years of teaching English has always seen consistency as what separates the most successful students from the rest. Find a language habit that you can follow even when you’re tired, sick or madly in love.
Play house with the language. The more you invite a foreign language into your daily life, the more your brain will consider it something useful and worth caring about. “Use every opportunity to get exposed to the new language,” says Russian translator Olga Dmitrochenkova. Label every object in your house in this language, read kids’ books written in it, watch subtitled TED and TEDx talks, or live-narrate parts of your day to an imaginary foreign friend.
Let technology help you out. Dmitrochenkova has a great idea: “A funny thing like resetting the language on your phone can help you learn new words right away,” she says. Ditto for changing the language on your browser. Or you can seek out more structured learning opportunities online. Dutch translator Els De Keyser recommends Duolinguo for its gamified approach to grammar, and Anki for memorizing vocabulary with its “intelligent” flashcards.
Think about language-learning as a gateway to new experiences. To Spanish translator Sebastián Betti, learning a language has always been about focusing on the experiences that the new language would open up, from “visiting theme parks, attending air shows, enjoying cowboy poetry and folk-rock festivals, to learning about photo-essay techniques.” In other words, he thinks of fun things that he wanted to do anyway, and makes them into a language-learning opportunity. Many of our translators shared this advice. Italian and French translator Anna Minoli learned English by watching undubbed versions of her favorite movies, while Croatian translator Ivan Stamenković suddenly realized he could speak English in fifth grade, after years of watching the Cartoon Network without subtitles. So the next time you need a vegan carrot cake recipe, find one in the language you’re trying to learn.
Make new friends. Interacting in the new language is key — it will teach you to intuitively express your thoughts, instead of mentally translating each sentence before you say it. Find native speakers near you. Or search for foreign penpals or set up a language tandem online, where two volunteers help one another practice their respective languages.
Do not worry about making mistakes. One of the most common barriers to conversing in a new language is the fear of making mistakes. But native speakers are like doting parents: any attempt from you to communicate in their language is objective proof that you are a gifted genius. They’ll appreciate your effort and even help you. Nervous about holding a conversation with a peer? Try testing your language skills with someone a little younger. “I was stoked when I was chatting with an Italian toddler and realized we had the same level of Italian,” recalls German translator Judith Matz. And be patient. The more you speak, the closer you’ll get to the elusive ideal of “native-like fluency.” And to talking to people your own age.

More good reasons to read

Reading about something and experiencing it firsthand are not all that different in your brain.

From e-180 mag
When I was little, my mother told me a story of how my father’s boss once drove them to his house for dinner. “As we passed houses along the suburban street, I saw one that was made of angel stone – you know that awful fake stone – and I blurted out how I hated angel stone. I said it to fill up the silence. And almost as soon as the words were out of my mouth, didn’t we pull into the driveway of a huge, angel stone house. I could’ve died.”

Even though I was only ten, I pictured my young mother, eager to do her part to impress the boss. Felt her embarrassment in the back of the dark car, saw my father’s profile as he turned, heard the uncomfortable silence as the boss switched off the ignition. In this simple story, without my mother ever having to summarize, I learned to keep my mouth shut about such things until I knew where someone lived.

When someone tells us a story, they transfer their experience directly into our brains. We feel what they felt. Annie Murphy Paul explains in Your Brain on Fiction that the brain “does not make much of a distinction between reading about an experience and encountering it in real life; in each case, the same neurological regions are stimulated”.


What is the best way to teach writing?

According to recent research, explicit grammar instruction doesn’t improve writing skill, but more time spent writing does.


To teach kids to write well, you need to ask them to write a lot. You’re not going to become a great basketball player unless you play a lot of basketball. The evidence is strong that this is true for writing too. Five studies of exceptional literacy teachers found that great teachers ask their students to write frequently. In nine separate experiments with students, 15 additional minutes of writing time a day in grades two through eight produced better writing. Seventy-eight percent of studies testing the impact of extra writing found that student’s writing quality improved.

Several studies found unexpected bonuses from extra writing time. Not only did writing quality improve, so did reading comprehension. Another cluster of studies proved that writing improves a students’ mastery of the subject; the act of writing helps you learn. (Another reason for teachers to refrain from spoon-feeding printed notes to students.)

continue reading

Sleep is more important than studying

If you want to benefit more from the previous day’s activities, then you need to get a good night’s sleep according to research.

Getting enough sleep is an under-valued but crucial part of learning. Contrary to students’ belief that staying up all night to cram for an exam will lead to higher scores, truth is, the need for a good night’s rest is even more important than finishing homework or studying for a test.

A recent study in the journal Child Development showed that sacrificing sleep in order to study will actually backfire. The study followed 535 Los Angeles high school students for 14 days, tracking how long they slept, as well as how well they understood material being taught in class and how they performed on a test, quiz, or homework.

“Although the researchers expected that extra hours of studying that ate into sleep time might create problems in terms of students’ understanding of what they were taught in class, they were surprised to find that diminishing sleep in order to study was actually associated with doing more poorly on a test, quiz, or homework,” Science Daily wrote.

“Reduced sleep … accounts for the increase in academic problems that occurs after days of increased studying,” said UCLA scientist Andrew Fuligni. “Although these nights of extra studying may seem necessary, they can come at a cost.”

source: mindshift

Language acquisition vs learning

More research suggesting that the teaching of grammar explicitly is not especially useful, and that the best way to master a second language is through massive comprehensible input.


Language and literacy can be”acquired” or “learned.” “Acquisition” occurs subconsciously: While it is happening, you are not aware it is happening, and after it has happemed, the knowledge is represented subconsiously in your brain. In contrast, “learning” is conscious; it is “knowing about” the language. When we talk about “rules” and “grammar” we are usually talking about “Learning.”

Acquired competence plays a much larger role in language use than learned competence does. Acquired competence provides our fluency and nearly all of our accuracy when we speak or write in a second language. Learned competence makes only a small contribution to our grammatical accuracy, and only when stringent conditions are met: We must consciously know the rule, which is daunting considering the complexity of the grammar of any language, we must have time to apply the rule, which is not usually available in conversation, and we must be thinking about correctness, or focussed on form.

This is not to say that grammar teaching is bad and must be forbidden: The point is that it is limited: Only a small part of the grammatical system of any language can be consciously learned, it takes time and effort to retrieve grammatical rules from our memory and apply them, and this can only happen when we are thinking about formal correctness. These severe conditions are met on grammar tests, and it is here where see clear evidence of the use of consciously learned rules (Krashen, 1981). Consciously learned rules are also of some help in editing, the final stage of the composing process.

Motivation not necessarily key

Motivation may not be among the most important factors in second language acquisition. Good thing, since very few of our students are actually interested in studying.

According to Krashen;
“I hypothesize that for most people, motivation plays no role in successful language acquisition. Rather, language acquisition is the result of doing something else: It is the result of obtaining truly interesting, or “compelling” comprehensible input. When this happens, our focus is NOT on improving in another language: Our focus is on the message. In fact, it can be hypothesized that language acquisition occurs most efficiently when the message is so compelling that the acquirer is not even aware that it is being delivered in another language. …

source: Krashen

Language Acquisition without Speaking and without Study.

Massive, compelling, self-chosen input may be key to language acquisition. This article refers to video input, but the same case has been made for extensive reading.

Christy Lao and Stephen Krashen
Journal of Research of Bilingual Education Research and Instruction 16(1): 215-221. 2014.
This paper describes a case of second language acquisition without speaking, without instruction, and without any kind of study. The subject, in fact, disdained study.
Paul is a young man, now a teenager, growing up in a Cantonese-speaking family in California. His parents are both native speakers of Cantonese, but highly proficient in English, and his mother speaks Mandarin very well. His grandparents live with the family and speak Cantonese with Paul and his brother.
Cantonese and Mandarin are different languages. They are related, and share some common vocabulary, but they are not completely mutually comprehensible. With the help of context, Cantonese speakers are able to understand a limited amount of Mandarin and vice versa.
Today, as a teenager, Paul speaks Mandarin quite well, in addition to Cantonese and English. He has a Cantonese accent when he speaks Mandarin and makes only a few errors. When Mandarin-speaking guests are at his home, he has no trouble conversing on everyday topics, and on occasional visits to China with his family he is comfortable speaking Mandarin.
This paper describes how Paul did it. Nearly all of his exposure to Mandarin has been through media, through TV and CD’s, with no classes, no study, and no interaction.
When Paul was a baby, his grandmother took care of him most of the time. Grandma liked to sing Paul lots of Cantonese and Mandarin songs and they watched Chinese MTV for children, which was in Mandarin.

source: Krashen