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)