85 表示能力或可能性：can/could/be ableto Track085
85 表示能力或可能性：can/could/be ableto Track085
（1）表示現(xiàn)在或?qū)碛心芰ψ瞿呈?/strong>
can表示因為具備某些特點或條件某人能夠完成某件事，或某事是可能存在的。所以can既表示有能力，也表示可能性。（注意：這里的“可能”與后邊討論的“推測”是不同的。）
例句
a. Bob can play the piano. He has taken lessons for many years.
（后天獲得的能力）
b. John is strong. He can lift that heavy box. （能力）
c. A fish can’t walk, but it can swim. （天賦的能力）
d. Dogs can bark, but they cannot talk. （天賦的能力）
e. The theater can seat 10,000 people.（可能）
這個劇院可容納一萬人。
f.I can walk to school. It’s not far. （可能）
g. You can see fish at an aquarium（水族館）. （可能）
h. You can buy stamps at the post office, but you can’t buy shoes there.（可能）
注：表示現(xiàn)在有能力做某事，一般不用be able to。
（2）表示過去有能力做某事
在表示能力時，could可以作為can的過去式來表示過去有能力做某事。（注意：如果不表示能力，could則不表示過去。例如could可以表示現(xiàn)在的“許可”“推測”。）
例句
a. Our son could talk when he was two years old. （表示過去的能力用can的過去式could）
b. I could run fast when I was a child, but now I can’t.
c. In those days few workers could support their families.
那時很少有工人能夠養(yǎng)家糊口。
（3）在表示 “過去有能力做某事” 時，could和was/were able to的用法區(qū)別
1）could只能表示過去“一般的能力，總的能力”。所謂“一般的能力 (general ability)”，即我們在過去想干什么就隨時可以干什么。（這時，我們也可用was/were able to。）
例句
a. I could/was able to recite several poems when I was 3 years of age.
我在三歲時就能背誦幾首詩。
b. I could/was able to run fast when I was a child, but now I can’t.
小時候我能跑得很快，但現(xiàn)在不行了。
c. He could/was able to pull down a bull and was acknowledged as a man with superman strength.（我們還可以說：He used to be able to…）
他那時能拉倒一頭牛，被公認為是具有神力的人。
2）而要表示在過去某個特定場合所表現(xiàn)出的“特定的能力，具體的能力”，或表示某人在某一場合設(shè)法成功地完成了某件事，而非表示泛指的能力時，我們要用was/were able to。此時，was/were able to意思相當于succeeded in doing或managed to do。
（When used to denote past ability, COULD does not refer to a single instance of ability on a particular occasion, but rather, it signifies an ability in a very general sense. The successful demonstration of ability on a particular past occasion is expressed by means of “be able to”, “manage to ”, “succeed in”,etc.）
下面例句中均不能用could：
a. With the aid of the wood, he was able to swim across the river.
借助那塊木頭，他游到了河的對岸。
b. I applied everywhere and finally I was able to get a good job.
我到處應(yīng)聘，最后找到了一份好工作。
c. He hurried to the station and was able to catch the train .
他匆匆忙忙趕到車站，趕上了火車。
d. The fire spread through the building quickly but everybody was able to escape. = …everybody managed to escape.
大火很快蔓延到整棟大樓，但是人們還是都逃了出來。
e. The two boys tried many ways to catch that sly fox and were able to do so at last .
兩個男孩試用了多種方法去抓那只狡猾的狐貍，終于成功了。
f.Although the pilot was badly hurt he was able to explain what had happened.
盡管飛行員的傷勢很嚴重，但是他還是解釋了發(fā)生的一切。
g. Tom has started an exercise program. He was able to run two miles yesterday without stopping or slowing down.
湯姆開始了訓(xùn)練計劃，他昨天跑了兩英里，中途沒有停也沒有放慢速度。
3）在否定句中could 和was/were able to可以互換，也就是說在否定句中它們就不存在上述區(qū)別了。
例句
a. I applied everywhere but couldn’t get any good job.
b. The fire spread through the building quickly and people couldn’t escape.
can表示因為具備某些特點或條件某人能夠完成某件事，或某事是可能存在的。所以can既表示有能力，也表示可能性。（注意：這里的“可能”與后邊討論的“推測”是不同的。）
例句
a. Bob can play the piano. He has taken lessons for many years.
（后天獲得的能力）
b. John is strong. He can lift that heavy box. （能力）
c. A fish can’t walk, but it can swim. （天賦的能力）
d. Dogs can bark, but they cannot talk. （天賦的能力）
e. The theater can seat 10,000 people.（可能）
這個劇院可容納一萬人。
f.I can walk to school. It’s not far. （可能）
g. You can see fish at an aquarium（水族館）. （可能）
h. You can buy stamps at the post office, but you can’t buy shoes there.（可能）
注：表示現(xiàn)在有能力做某事，一般不用be able to。
（2）表示過去有能力做某事
在表示能力時，could可以作為can的過去式來表示過去有能力做某事。（注意：如果不表示能力，could則不表示過去。例如could可以表示現(xiàn)在的“許可”“推測”。）
例句
a. Our son could talk when he was two years old. （表示過去的能力用can的過去式could）
b. I could run fast when I was a child, but now I can’t.
c. In those days few workers could support their families.
那時很少有工人能夠養(yǎng)家糊口。
（3）在表示 “過去有能力做某事” 時，could和was/were able to的用法區(qū)別
1）could只能表示過去“一般的能力，總的能力”。所謂“一般的能力 (general ability)”，即我們在過去想干什么就隨時可以干什么。（這時，我們也可用was/were able to。）
例句
a. I could/was able to recite several poems when I was 3 years of age.
我在三歲時就能背誦幾首詩。
b. I could/was able to run fast when I was a child, but now I can’t.
小時候我能跑得很快，但現(xiàn)在不行了。
c. He could/was able to pull down a bull and was acknowledged as a man with superman strength.（我們還可以說：He used to be able to…）
他那時能拉倒一頭牛，被公認為是具有神力的人。
2）而要表示在過去某個特定場合所表現(xiàn)出的“特定的能力，具體的能力”，或表示某人在某一場合設(shè)法成功地完成了某件事，而非表示泛指的能力時，我們要用was/were able to。此時，was/were able to意思相當于succeeded in doing或managed to do。
（When used to denote past ability, COULD does not refer to a single instance of ability on a particular occasion, but rather, it signifies an ability in a very general sense. The successful demonstration of ability on a particular past occasion is expressed by means of “be able to”, “manage to ”, “succeed in”,etc.）
下面例句中均不能用could：
a. With the aid of the wood, he was able to swim across the river.
借助那塊木頭，他游到了河的對岸。
b. I applied everywhere and finally I was able to get a good job.
我到處應(yīng)聘，最后找到了一份好工作。
c. He hurried to the station and was able to catch the train .
他匆匆忙忙趕到車站，趕上了火車。
d. The fire spread through the building quickly but everybody was able to escape. = …everybody managed to escape.
大火很快蔓延到整棟大樓，但是人們還是都逃了出來。
e. The two boys tried many ways to catch that sly fox and were able to do so at last .
兩個男孩試用了多種方法去抓那只狡猾的狐貍，終于成功了。
f.Although the pilot was badly hurt he was able to explain what had happened.
盡管飛行員的傷勢很嚴重，但是他還是解釋了發(fā)生的一切。
g. Tom has started an exercise program. He was able to run two miles yesterday without stopping or slowing down.
湯姆開始了訓(xùn)練計劃，他昨天跑了兩英里，中途沒有停也沒有放慢速度。
3）在否定句中could 和was/were able to可以互換，也就是說在否定句中它們就不存在上述區(qū)別了。
例句
a. I applied everywhere but couldn’t get any good job.
b. The fire spread through the building quickly and people couldn’t escape.
