Confusion about explaining the use of could/couldn't/can't

[sjaakspaak]

Hi there,

As a rookie teacher I need to explain the difference between can/could and can't/couldn't to a class of (non-native) kids aged around 11/12 years old. Important detail to know: they know nothing about the past tense yet! In their textbook the distinction is described as follows:

Use can when showing: ability
Use can when: asking a question politely; proposing something; showing possibility.

I have no problems explaining clear sentences like:
- I'm feeling ill, so I can't come to your house this afternoon.
- Could you pass the salt?
- We could go swimming tomorrow.


However, I do have a lot of trouble explaining sentences where the key to textbook exercises (fill in the blanks - the blanks being the bold words) says these are the only correct answers:

- Rick probably know which ingredients to use. Couldn't we ask him?
In my opinion can't or could would be correct as well. Since you don't know the answer, and there 's no way of telling if the answer is going to be positive or negative.

- We need to make an assignment for class tomorrow. Couldn't we work on it together?
Same reason for last example.

- Can I ask you a question?
In my view could or may would both be correct as well.

Note: these are all textbook sentences said to be correct. Especially when sentences start with couldn't I don't really know how to explain to kids why this, and only this, should be the correct answer.


I hope someone can help me with this issue
Thanks in advance.

[jutfrank]

The first thing to remember is that 11-year-old kids are not big fans of any kind of explanation. I wouldn't actually bother trying to explain anything. Just tell them how to say what you want them to say. Make sure that the function is very clear, give them some sentence frames, and then let them loose with practice.

But, to address your questions ...

- Rick probably know which ingredients to use. Couldn't we ask him?
In my opinion can't or could would be correct as well. Since you don't know the answer, and there 's no way of telling if the answer is going to be positive or negative.

Right. That's why this is a near-useless example. Don't use it.

- We need to make an assignment for class tomorrow. Couldn't we work on it together?
Same reason for last example.

Right. See my comment above. This one is even worse than near-useless, actually. It's also unnatural. We don't tend to use couldn't for suggestions like this. Use Shall instead.

- Can I ask you a question?
In my view could or may would both be correct as well.

Right. But you don't really need to mention that. Just tell them to use Can. You might want to tell them that they can use May too, if they want to be deferential, but you really don't need to mention Could.

Note: these are all textbook sentences said to be correct. Especially when sentences start with couldn't I don't really know how to explain to kids why this, and only this, should be the correct answer.

I'm sorry you have such a poor textbook to work with. Which one is it?

[sjaakspaak]

Thanks for your quick and complete reply. I can definitely work with this! It's comforting to get confirmation about my doubts about some examples and exercises. The method is called New Interface. It's actually pretty good and clear most of the time if I'm honest. Grammar is explained in a clear and easy way, and most exercises in the workbook leave little room for random mistakes. It's just the can/could part that's been bugging me so far. I feel like they don't want to explain all of the possibilities on this subject (yet), because the quantity of choices might confuse the children. I think this subject might come back in the workbook later, then they will probably elaborate on the possibilities.

Thanks again!