George has travelled a lot. He *** speak four languages. (can/be able to)
I haven't *** sleep very well recently. (can/be able to)
Sandra *** drive but she hasn't got a car. (can/be able to)
I can't understand Martin. I've never *** understand him. (can/be able to)
I used to *** stand on my head but I can't do it now. (can/be able to)
I can't see you on Friday but I *** meet you on Saturday morning. (can/be able to)
Ask Catherine about your problem. She might *** help you. (can/be able to)

George has travelled a lot. He can speak four languages.

I haven't been able to sleep very well recently.

Sandra can drive but she hasn't got a car.

I can't understand Martin. I've never been able to understand him.

I used to be able to stand on my head but I can't do it now.

I can't see you on Friday but I can meet you on Saturday morning.

Ask Catherine about your problem. She might be able to help you.