Let me stay here till Jeannie comes home.
If you mention an event in a time clause that will happen before an event referred to in the main clause, you use the present perfect in the time clause, not the future perfect.
For example, you say When you have had your supper, come and see me, not When you will have had your supper, come and see me.
We won’t be getting married until we’ve saved enough money.
Come and tell me when you have finished.
8.10 The most common conjunction in time clauses is when. When is used to say that something happened, happens, or will happen on a particular occasion.
When the telegram came and I read of his death, I couldn’t believe it.
He didn’t know how to behave when they next met.
8.11 You can mention the circumstances in which something happens or happened by using when, while, or as.
The train has automatic doors that only open when the train is stationary. While he was still in the stable, there was a loud knock at the front door.
He would swim beside me as I rowed in the little dinghy.
Whilst is a more formal form of while.
We chatted whilst the children played in the crèche.
8.12 If you want to emphasize that something happened at a particular time, you can use It was followed by an expression such as six o’clock or three hours later, followed by a when-clause.
For example, instead of saying I left at six o’clock, you say It was six o’clock when I left.
It was about half past eight when he arrived at Gatwick.
It was late when he returned.
This is an example of a split sentence. Split sentences are explained in paragraphs 9.25 to 9.30.
repeated events
8.13 If you want to say that something always happened or happens in particular circumstances, you use when, whenever, every time, or each time.
When he talks about Ireland, he does sound like an outsider.
Whenever she had a cold, she ate only fruit.
Every time I go to that class I panic.
He looked away each time she spoke to him.
8.14 You use an expression such as the first time, the next time, or the third time to say that something happened during one occurrence of an event.
The last time we talked he said he needed another two days.
The next time I come here, I’m going to be better.
events in sequence
8.15 You can also use when, after, or once to talk about one event happening immediately after another.
When his wife left him he suffered terribly.
Stop me when you’ve had enough.
The turtle returns to the sea after it has laid its eggs.
Once the damage is done, it takes many years for the system to recover.
If you want to say how long one event happened after another, you put a noun phrase such as two days or three years in front of after.
Exactly six weeks after she had arrived, she sent a cable to her husband and caught the plane back to New York.
As soon as, directly, immediately, the moment, the minute, and the instant are all used to talk about one event happening a very short time after another.
They heard voices as soon as they pushed open the door.
The minute someone left the room, the others started talking about them.
Immediately the meal was over, it was time for prayer.
8.16 When you want to say that something happened, happens, or will happen at an earlier time than something else, you use before.
It was necessary for them to find a home before the cold weather arrived.
Before they moved to the city she had never seen a car.
If you want to say how long one event happened before another, you put a noun phrase such as three weeks or a short time in front of before.
He had a review with the second organiser, about a month before the report was written.
Long before you return she will have forgotten you.
8.17 When you are telling a story, you sometimes want to say what was happening when a particular event occurred. You first say what was happening, then add a clause beginning with when in which you mention the event.
I had just finished my meal when I heard voices.
He was having his dinner when the telephone rang.
If you want to say that one event happened a very short time after another, you use a clause in the past perfect, followed by a time clause in the past simple. After had in the first clause, you put no sooner or hardly.
When you use no sooner, the time clause begins with than.
I had no sooner checked into the hotel than he arrived with the appropriate documents.
When you use hardly, the time clause begins with when or before.
He had hardly got his eyes open before she told him that they were leaving.
No sooner or, less frequently, hardly can be put at the beginning of the first clause, followed by had and the subject.
No sooner had he asked the question than the answer came to him.
Hardly had he settled into his seat when Alan came bursting in.
Hardly had he got on his horse before people started firing at him.