tailieunhanh - Ngữ pháp tiếng anh - Can, could, be able to

Đây là tài liệu ngữ pháp tiếng anh cơ bản cấu trúc cấu "can, could, be able to" gửi đến các bạn độc giả tham khảo. | Can, could, be able to and be allowed to. Can, could and be able to : talking about ability. We sometimes use be able to instead of can and could to talk about ability. However, we avoid be able to. _when we talk about something that is happening as we speak: _ before passives: _when the meaning is “know how to” : If we talk about a single achievement, rather than a general ability in the past, we usually use be able to rather than could. However, could is usually more natural-- _ in negative sentences : _ with verbs of the senses – . feel, hear, see, smell, taste –and verbs of “thinking”—. believe, decide, remember, understand: _after the phrases the only thing/place/time, and after all when it main “the only thing” : _ to suggest that something almost didn’t happen, particularly with almost, hardly, just, nearly: Watch me, Mum; I can stand on one leg( NOT I’m able to stand on one leg.) CDs can now be copied easily.( rather than CDs are now be copied easily. Can you cook ? ( rather than Are you able to cook ?) Sue could play the flute quite well.(or was able to ; a general ability.)AND She swam strongly and was able to cross the river easily, even though it was swollen by the heavy rain.(not She swam strongly and could cross ; a specific achievement.) I tried to get up but I couldn’t move. I could remember the crash, but nothing after that. All we could see were his feet. I could nearly touch the ceiling. Can and could: talking about possibility. To talk about the theoretical possibility happening we use could not can. However, we can use can not could, to say that something is possible and actually happens, We use can’t, not couldn’t, to say that something is theoretical or actually impossible. We use can to indicate that there is a very real possibility of a future event happening. Using could suggest that something is less likely or that there is some doubt about it. It could be expensive to keep a cat. There can’t be many people in the world who haven’t watched TV. We can stay with Jim in Oslo.(=we will be able to stay. ) _ We could stay with Jim in Oslo.(=it’s possible; if he’s there.) Could and be allowed to: talking about permission. To say that in the past someone had general permission to do something—that is, to do that at any time—we can use either could or was/were allowed to However , to talk about permission for one particular past action, we use was/were allowed to , but not couldn’t. In negative sentences, we can use either couldn’t or wasn’t/weren’t allowed to to say that permission was not given in general or particular situations: Anyone was allowed to fish in the lake when the council owned it. We wasn’t/weren’t allowed to open the presents until Christmas morning. the end future Completed by Le Hoang Nham