By The Time + Past Perfect Or Simple Past?

There may be occasions where it is necessary or desirable to use any one of the possible combinations of past and past perfect, so I would not call it a rule. Nevertheless, the "rule", such as it is, does apply equally to before, after, and by the time, in my opinion.

Patterns in which both clauses are in the past perfect seem particularly awkward to me.
Patterns with the past in the main clause and the past perfect after before, after, or by the time seem less awkward, but less used than other possible combinations.
The patterns with the main clause in either simple past or past perfect with the subordinate clause in the simple past seem to me to be the most useful patterns.

CJ

CalifJim,

Thanks for your response.

What do you think about patterns with both clauses in simple past?

Examples:

1. Millions of years ago, dinosaurs roamed the earth, but they became extinct by the time humankind first appeared.

I would prefer:

She had already left by the time he arrived.

You may want to read this current related thread:

http://www.EnglishForward.com/English/When/drkdc/Post.htm

and check Swan re tense simplification.

You may find yourself quotations from literature involving "by the past" by performing a search at:



with:

site:literaturepost.com "by the time"

You will find enough examples even of past perfect/past perfect combinations, such as:

------
The Silverado Squatters by Stevenson, Robert Louis - Chapter 9

by the time I had finished, the sun had begun to go down behind the
mountain shoulder, the platform was plunged in quiet shadow, and a ...

www.literaturepost.com/chapter/20193.html

----

Alice in Wonderland by Carroll, Lewis - Chapter 11

Dormouse turned out, and, by the time they had settled down again, the
cook had disappeared. `Never mind!' said the King, with an air of
great relief. ...

www.literaturepost.com/chapter/339.html

----
Gaspar Ruiz by Conrad, Joseph - Chapter 5

By the time the soldiers had fired a third volley into the slightly
stirring heaps of the slain, the sun had gone out of sight, and almost
...

www.literaturepost.com/chapter/6648.html
----

I took these as the most appealing ones:

She had left before he arrived.

She left after he had arrived.

She had left by the time he arrived. i.e. She had left no later than the time he arrived

She had left that city since he arrived there. i.e. She had left that city since the time (when) he arrived there.

Anything inappropriate??

Do these preferences sound intolerably pedantic???

What do you think about patterns with both clauses in simple past?

They are among the most useful, I think, and they sound quite natural. See previous post.

No. had already is common in that context, but just already is also fine in American English. Personally, I would have chosen had already.
I believe the British may have different preferences.

in years is a period of time ending at the present moment. This is the exact situation which calls for a perfect tense.

CJ

In first sentense 1.event is leaving,then he arrive.this sentence can be used (before he arrived,she left.)...but ın second sentence before she left ,he arrived.that is..