§ 46б.
В косвенной речи, если вводящий ее глагол стоит в прошедшем времени, преднастоящее и простое прошедшее заменяются предпрошедшим. При этом наречие ago, часто сопутствующее глаголам в прошедшем времени (Past Tense), заменяется наречиями before –1. "I have already read that book."
She told me that she had already read that book.
2. "They left the district a few months ago."
I was told that they had left the district a few months before (earlier, previously).
3. "Where have you been? What have you been doing?"
Не asked me where I had been and what I had been doing.
4. "George died two days ago."
They told me that George had died two days before.
5. "I visited Naples two years ago."
Mary told me that she had visited Naples two years before.
§ 46в.
Если последовательность событий и так ясна, можно обозначать оба действия глаголами в одной форме простого прошедшего времени (Past Tense). Так бывает, как правило, в сложноподчиненных предложениях с союзом before.Не opened the window before he got into bed.
The bus started just before I reached the bus stop.
При других союзах большей частью приходится употреблять глаголы в предпрошедшем времени (Past Perfect Tense), чтобы было ясно, какое из двух событий или действий совершилось раньше другого.
When he "had had his supper, he went to bed.
Сравните следующие два примера: в первом оба действия совершаются одновременно, во втором одно действие следует за другим.
When the Queen entered the hall, the orchestra played the National Anthem.
When the Anthem had been played, the concert began.
В сложноподчиненных предложениях, где говорится о двух действиях, из которых одно предшествовало другому, употребляются следующие союзы: when, before, after, until, once, now that и as soon as. Нередко одно и то же отношение можно выразить несколькими способами, при помощи разных союзов. Приводим несколько примеров.
1) a) When I reached the station, the train had already left.
b) I reached the station after the train had left.
c) I didn’t reach the station until after the train had left
d) The train (had) left before I reached the station.
2) a) When we got to the hall, the concert had already started.
b) We got to the hall after the concert had started.
c) We didn’t get to the hall until after the concert had started.
d) The concert (had) started before we got to the hall.
3) a) For several years after Green (had) left college, he was employed by an insurance company.