Can, Can't and To Be Able to

In NI1 (Englihs File-unit 4A)  we've been working with this modal and we've seen that as CAN is a defective verb we should use TO BE ABLE TO + infinitive if we want to use it in some verbal forms such as the following ones:

• I haven't been able to finish my homework yet
• I'd like to be able to do it soon
• I love being able to do my homework on time
• I'll be able to do it next time

Although it is possible to use TO BE ABLE TO in present and past simple, it sounds a bit formal and it's more frequent (and easier) to use CAN and COULD. But whenever we need infinitive, gerund or past participle forms, we must use the forms of to be able to because CAN doesn't have those forms. If you need some more information about this point, you can click here

If you want to practise with this modal and to be able to you have these exercises:

• exercise 1        exercise 2        exercise 3

We've also worked with pronunciation in class and here you are a video which helps you to pronounce CAN and CAN'T properly; click here or here