How to teach 'can' and 'can't' for ability

Summary: How to make 'can' and 'can't' lessons really useful for students, including how to identify and deal with common problems with the language of ability.

“Can” and “can’t” in sentences like “I can speak three languages” and “I can’t skate (well)” is incredibly easy to teach and practise. Partly for that reason, this language point is often taught without a lot of thought being putting in to how to do so well. This article gives hints on how to present and practise this point in a way which focuses on what students really need to know about the language and the problems that they actually have with it. 

Dealing with typical student problems with can/ can’t for ability

If you present it in the ways explained below, few students have problems with the fundamental meaning of “I can ski” and “I can’t ride a bike”. Instead, the problems with the language tend to be:

-       The pronunciation of “can” in positive and negative statements

-       Confusions between “do” and “can” (especially in questions and short answers)

-       Confusions between the different past forms of “can”

-       Confusion with other uses of “can” such as “Can I have another cup of tea, please?”

Dealing with problems with the pronunciation of can and can’t

The most important student problem with can and can’t for ability is the inability of many learners to tell if a native speaker is saying “I can do this on my own” or “I can’t do this on my own”. Some students also have problems making their own meanings clear in such sentences, with the listener maybe being amazed at their linguistic abilities when actually they are explaining their failed attempts at learning languages! Making a distinction between “can” and “can’t” in statements is particularly difficult in sentences like “He can’t turn around” and “We can’t dry these clothes before we go out” when the word after “can’t” starts with “t” and “d”, as the final “t” in “can’t” becomes impossible to hear. Fortunately, there are other distinctions between positive and negative sentences that you can teach students to listen for and try to produce.

In most southern British accents such as RP/ BBC English/ Queen’s English, “can’t” has a long “ar” vowel sound like “car” and “farther”, making it clearly different from the short “a” sound of “man” and “at” in “can”. Unfortunately in most other accents, including American ones, the vowel sounds in “(Yes, I) can” and “(No, I) can’t” are the same short “a” sound as “man” and “at”. Luckily, in normal positive sentences like “I can stand on my head”, the “can” usually has the weak “er” sound at the end of “computer” known as “schwa”, making “I can swim” almost like “I cn swim”. This makes the “can” in positive statements very different from the “at”/ “man” sound in “Yes, I can”, and so easy to distinguish from “can’t”. The reason for this weak “er” sound in positive statements is that the stress in the sentence is on the main verb(s), e.g. “stand” and “head”, leaving “can” with an unstressed schwa form. In contrast, in “Yes, I can” and “I can’t swim” the “can” and “can’t” are stressed. This change to the weak schwa form when “can” is unstressed is the same thing that happens with other grammar words like “and”, “a” and “of” when they are not stressed, all of which have a weak schwa form in those cases.

Although it is worth spending some time on listening for and producing the weak “er” sound in “I can jump one metre fifty”, it is actually the stress patterns which are more important for understanding and producing positive and negative sentences. For example, the stress of “I can stand on my head” is ooOooO, but the stress of “I can’t stand on my head” is oOoooO. You can emphasise how easy it is to recognise if the sentence is positive or negative using this system by getting students to recognise the patterns just from a hummed sentence or even just from the teacher tapping out the sentence on the desk, without even needing to use the words “can” and “can’t”. 

Dealing with confusions between do and can

As students have probably recently been studying Present Simple forms like “What do you eat for breakfast?” when they study “can” for the first time, question forms like “Do you can juggle?” X are fairly common at that stage. Even students who get “Can you…?” right can sometimes respond to “Can you…?” questions with the incorrect short answers “Yes, I do”/ “No, I don’t”. Simple correction is usually enough to solve this without the need for any explanation, which can get a bit involved. 

If students do need an explanation of why we don’t say “Do you can…?” etc, this is best illustrated with negative forms, as students rarely say “I don’t can go…” In negative sentences, the auxiliary verbs “do” and “can” in “I don’t go to any clubs” and “I can’t speak German” go before the main verbs “go” and “speak”. Those same auxiliary verbs are also used at the beginning of questions like “Can you whistle?” and “Do you eat cereal for breakfast?” The same is obviously true for Wh- questions like “What do you do after breakfast” and “What languages can you speak?” and also works for short answers like “Yes, I do" and “No, I can’t”. 

Dealing with problems with past forms of can for ability

Uniquely among languages that I know about, English has three distinct past forms of “I can open the door” with important differences in meaning between them, namely “I could open the door”, “I was able to open the door” and “I managed to open the door”. With these examples, the “I could…” probably means I used to have the ability to open the door but then it got stuck, while “I managed to…” probably has the very different (in fact almost opposite) meaning that I struggled but finally successfully opened the door. Students often use “I could…” for this latter meaning. For example, students often make mistakes like “The door was locked but I could climb in through the window” to mean “The door was locked but I managed to climb in through the window”, which could be misinterpreted to mean I had that ability to get in through the window but decided not to. 

Luckily, “I was able to…” has the meanings of both “I could…” and “I managed to…” and so is a safe choice if students aren’t sure which to use. That safe option and the fact that misuse of “I could…”is very common among non-native speakers with little or no confusion means I wouldn’t bother tackling this point at under Intermediate or Upper Intermediate level, and certainly not in the same course as introducing can and can’t for ability form for the first time. 

Dealing with confusions between can for ability and other uses of can

“Can” obviously has many uses in English other than the ability meaning of “Humans can’t breathe in space” and “I can touch my nose with my tongue”. These other uses include requests like “Can you pass me the salt?” and offers like “Can I help you?” Personally, I can see almost no connection between these different uses of “can”. I also find attempts by textbooks to put different uses of “can” together in one unit to be confusing for students. Some books go further and attempt to explain that “Can I have another cup of tea?” in some way means “Am I able to have another cup of tea?”, which just seems downright wrong. For one thing, unless we are joking we rarely answer requests like “Can you pass me the salt, please?” with “Yes, I can”/ “No, I can’t”! 

My recommendation for avoiding confusion between these different uses of “can” is mainly just to teach them far apart from each other. If students bring up the similarities and differences between the uses of “can” at some point, I tend to emphasise the differences such as the “Can I help you?” “No, you can’t” mistake. In fact, I often go further and tell them to treat the various uses of “can” as totally different words with the same spelling and pronunciation. 

Connected to this point, you also need to be very careful that the example sentences, communicative activities etc that you use really are about can and can’t for ability, and that you don’t include sentences that drift into other meanings. For example, I nearly accidently put the making arrangements sentence “I can fit you in after 5 p.m.” and the offer “I can carry this (for you) (if you like)” into this article as examples of can for ability! 

Dealing with other problems with can for ability

Very occasionally students might try to make a third person S form of can with sentences like “He cans make bread” X. Once students are told that “can” is easier than that and never needs to be changed, they are usually quite happy to instantly drop the –s. 

How to present can/ can’t for ability

Every language I know has a clear translation for can/ can’t for ability, and this is one of the few grammar points where I use translation to clear up the meaning and save time. I usually do this by asking students to provide me with a translation that I can confirm or contradict (to avoid actually using other languages in the classroom myself). 

Ways of presenting can and can’t for ability with the minimum of translation include mimes and pictures which show people doing things well and totally failing to do things, e.g. falling off a skateboard or speaking fluent Chinese. Although mimes and pictures for “can’t” can be difficult to come up with, it is important they show someone actually failing at something. A picture of someone doing something with a cross through is no use to present and practise “can’t” as it can easily cause confusion with “I don’t ride a bike” (a common mix up for students). 

Most students will have already come across can for ability before, in which case you can elicit “I can’t use a computer” and “I can play basketball (very well)” straightaway and move straight onto typical problems like those mentioned above. If the form is totally new to them, you could put the positive and negative versions of each sentence up on the board mixed up and get students to guess which sentence each mime or picture represents. Perhaps after asking students to come up with their own mimes or pictures to represent the same sentences, you can then erase the example sentences and use the same pictures or mimes to elicit those or similar sentences onto the board. If any explanation is needed, it can be during any of those stages. I tend to just respond on the day to whether and when students seem to need the language explained, avoiding all explanation if they seem to have got the meaning. 

After eliciting the basic positive and negative statement forms, you’ll probably want to move straight onto presenting the pronunciation of can and can’t in such sentences, probably with an emphasis on stress patterns as suggested in the student difficulties section above. You could also present question forms and short answers, especially if you want students to ask each other questions during the subsequent stages (always a good way of prompting real communication). 

Classroom practice for can/ can’t for ability

The main problem with thinking of classroom activities for this language point is quite a nice one to have – there are simply too many possible fun speaking activities! To make it easier to choose which practice activity to use in class, the most important factor to bear in mind is that students usually have no problem with basic understanding and production of this form. There is therefore no point spending even ten minutes of class time on students producing perfect “Can you…?” “Yes, I can” exchanges that teach them nothing. Instead, any practice of can and can’t needs to be focussed on actual student issues with this grammar point such as recognising positive and negative sentences. 

You can also make speaking practice of this point more useful by making sure there is other useful language in the activity. For example, you could introduce or practise the names of typical household objects by getting them to talk about different things that they can and can’t do with them, including some objects which they won’t know the names for, have false friends problems with and/or will have pronunciation problems with. Vocabulary which ties in well with can and can’t for ability includes:

-       Animals (“It can walk on two legs” for a gorilla, etc)

-       Machines and technology (“It can hover” for a drone, etc)

-       Classroom vocabulary (“You can make an aeroplane with it” for “paper” etc)

-       Food and cooking vocabulary (“You can fry it”, “You can’t eat it raw”, “You can make pasta sauce with it”, etc)

-       Verbs (including useful ones for particular groups of students such as engineers or business buzzwords like those you can drop into your job interview answers)

-       Places (“You can get money there” for a post office, etc)

-       Country names (“You can see the Leaning Tower of Pisa there”, “You can visit Universal Studios there”, etc)

-       Collocations (“do”/ “make”, “do”/ “play” with sports, etc)

-       Clothes (“You can’t wear them on your head. They can keep your feet dry” for “boots”, etc)

-       Materials (“It can stretch” and “You can make tyres from it” for “rubber”, etc)

As well as having a useful and relevant vocabulary focus, it is also possible to tie can/ can’t practice in with the previous or next language point, e.g. getting students to talk about what they can balance, hold, etc in their hand, on their shoulder etc for prepositions of position. Other grammar points which tie in well include have/ have got (“I have a paper clip. I can unlock the door with it” etc) and Present Simple (“I can this but I almost never do it” for “ride a bike”, etc).

The other possible way of making sure there is lots of good extra language, and also to add some useful skills practice, is to base at least part of your lesson around reading and/ or listening texts. Real life texts that have a fair bit of this language and can be edited to realistically provide more include articles about technology (e.g. a new robot), the Guinness Book of World Records, descriptions of (strange) animals, descriptions of substances such as metals, job ads, and calls for volunteers. For young learners, there are also lots of nice songs and picture books which include can and can’t, such as Head to Toe by Eric Carle and the accompanying song.

A more detailed guide to classroom activities will be available later.

Copyright © 2016

Written by Alex Case for

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