Would anyone be so kind as to answer my questions?
1) We normally use 'can' and 'could' to express general meaning, 'be able to' in the meaning 'manage' in a specific situation. It's clear. What is the difference between 'can' and 'be able to' in the Present? I asked this question but got answers like 'they are almost identical'. I would like to know how the sentences 'He can drive a car' and 'He is able to drive a car' differ.
2) All English grammar books written in Russia say that the Passive Voice is never used in Perfect Progressive Tenses, that is what they call the basics. On one site I've read that sentences like 'The car has been being washed for 2 hours' are also possible. Is that really so? When I searched this in Google, there were not so many examples. Where is the truth?
Thank you, Natalia
1..."Can" and "be able to" are very similar and are often interchangeable.
In your 'car' sentences, maybe one say that "can" emphasizes having the knowledge and practical training/experience needed to drive a car, while "is able to" emphasizes the present ability and availability to drive a car.
He can drive a car, but is not able to do so now because he has a broken ankle.
I don't want to overstate this 'difference' and I am not sure how many other people would make this distinction. Maybe someone else will offer an opinion.
2...I don't agree. Passive voice can be used with perfect progressive tenses. I have been receiving phone calls from him all day.
I don't think that "The car has been being washed for 2 hours" is a good sentence at all! 'The car has been getting a wash for 2 hours.' is fine.