3-24. Прошлое с can/could

 
1. Could употребляется для выражения способности что-то делать в прошлом, только если из контекста (например, есть другой глагол в форме прошедшего времени) очевидно, что речь идет именно о прошлом:

She [could read] Latin when she was twelve!
Не [could speak] German well when he was young, but he has forgotten most of his German now.
It [could be quite frightening if you were alone in our big old house.
She [could read] when she was four.
My grandmother [could sing] like an angel (можно догадаться, что это было в прошлом).
My last [car could] do 200 kph (слово ‘last’ указывает на прошлое).
In those days everybody [could find] a job (обстоятельство ‘in those days’ указывает на прошлое).

Можно употреблять was/were able to:

She [was able to read] when she was four.

2. Could употребляется в придаточных клозах и косвенной речи:

Can you help me? – What did you say? – I asked [if you could help me].
Can you give me a hand? – What? – I asked [if you could give me a hand].
[You could get a better job] if you spoke a foreign language.
I told you [I could use a typewriter].
I told him [I could help him].

3. Can/could выражает именно возможность что-либо совершить, поэтому, как правило, не употребляется для выражениях законченных в прошлом отдельных действий. В отношении таких действий could выражает сослагательность:

Тоm could pass the examination, we all were sure of that (Том мог сдать и мы были в этом уверены, но предложение не означает, что он его действительно сдал).
Tom could pass the examination (Том мог бы сдать экзамен, но тоже не значит, что он его сдал).

Для выражения законченных действий в прошлом можно употреблять

3.1. Просто Past Simple:

I found a really nice dress in the sale. (не ‘I could find... ’)
Torn passed the examination.
Harry swam across the river.
Аnn didn't catch her train.

(could в таких предложениях не употребляется)

3.2. Manage (предполагает трудности, которые пришлось преодолеть) и succeed:

I managed to run 10 km yesterday. (не ‘I could run 10 km yesterday... ’ )
I managed to buy a really nice coat yesterday. (не ‘I could buy a really nice coat yesterday’.)
After six hours' climbing, we succeeded in getting to the top of the mountain. (не ’… we could get to the top... ’ )
Torn succeeded in passing the examination.
Harry managed to swim across the river.
Anne didn't manage to catch the train.
Did you manage to get to the top of the mountain?
How did you manage to get here in time?
I managed to get /succeeded in getting all my clothes into the suitcase.

3.3. Обороты с get

Не got it done. (‘Не could get it done’ означает, что он мог бы это сделать).

3.4. Оборот be able to:

I was able to pass the examination.
How many eggs were you able to get? (не ‘...could you get?’)

4. Но could можно употреблять, выражая, что что-то не случилось в конкретном случае в прошлом

4.1. С глаголами see, hear, smell, taste, feel, understand, remember:

I [could smell] something burning.
I [could understand] everything she said.
Suddenly she realised she [could smell] something burning.
He spoke so quickly that I [couldn't understand] him at all.
Though I was sitting in the last row, I [could see] the film well.
I [could not] hear him.

4.2. В отношении единичного случая в придаточном клозе:

I'm so glad that you could come.

4.3. При употреблении отрицательной формы couldn't:

I managed to find the street, but I couldn't find her house.
Не said he couldn't come to the meeting.
The box was so heavy that I couldn't lift it.
Не said he was sorry he couldn't lend me the money.
I tried to lift the box but couldn't.

4.4. С наречиями hardly и only (так как они также имеют негативный оттенок).

She could hardly believe her eyes. I could only get six eggs.

5. Употребляется can't, а не couldn't, когда речь идет о том, что невозможно:

There can't be many people in the world who haven't watched television.
The doctor can't see you this morning; he's busy at the hospital.

6. Could+have+past participle указывает на неосуществленную в прошлом возможность:

The President was always available. We could see him at any time (мы могли его видеть)
You never came to see me. Why not? You could have seen me at any time (ты мог, но не делал).

You could have caught the train if you had hurried.
I could have married anybody I wanted to.
I was so angry I could have killed her!
Why did you jump out of the window? You could have hurt yourself.
I could have won the race if I hadn't fallen.
I could have kissed her if I'd wanted to.
Не could easily have done it.

Так можно выразить неудовольствие:

You could have helped me - why did you just sit and watch?
You could have told me you were getting married.

Отрицательное предложение показывает, что возможности что-то сделать не было вообще:

I couldn't have won, so I didn't go in for the race.
I couldn't have enjoyed myself more - it was a perfect day.

Такая конструкция иногда может выражать и предположение:

Who sent those flowers? – I'm not sure. It could have been your mother.

Предложение может относиться к настоящему времени:

He could have been Prime Minister now if he hadn't decided to leave politics.
We could have spent today at the seaside, but we thought it was going to rain, so we decided not to.

■ Иногда употребляется can+have+past participle:

I don't know where she can have gone.

7. Was/were able to предпочтительнее, когда речь идет о единичном достижении в прошлом, а не способности вообще (в этом случае можно употреблять и could и was/were able to):

She swam strongly and was able to cross the river easily, even though it was swollen by the heavy rain (не ‘She swam strongly and could cross...’)
He didn't want to buy a new suit but at last we were able to persuade him.
She wasn't able to pass the exam.

Sue could play the flute quite well/ Sue was able to play... (способность вообще)

Отрицательную форму couldn't можно употреблять в обоих случаях:

He couldn't play tennis.
We couldn't persuade him to buy a new suit.

8. Could звучит естественнее

8.1. В отрицательных предложениях:

I tried to get up but I couldn't move (естественнее, чем ‘...I wasn't able to move’.)

8.2. С глаголами физического восприятия (feel, hear, see, smell, taste) и выражающими умственную деятельность (believe, decide, remember, understand и т.п.):

I could remember the crash, but nothing after that (естественнее, чем ‘I was able to remember...’)

8.3. После the only thing/place/time и all, со значением 'the only thing':

All we could see were his feet. (естественнее, чем ‘All we were able to...’)

8.4. Выражая идею что что-то чуть не случилось, особенно с наречиями almost, hardly, just, nearly:

I [could nearly touch] the ceiling (естественнее, чем ‘I was nearly able to...’)