Past Perfect Simple vs Past Simple

Question

1. By the time he had reached the door, he remembered the pink diamond.
2. By the time he reached the door, he remembered the pink diamond.

Are both sentences grammatically correct?

Thank you!

Answer 1

In the first sentence the past perfect should be used in the main clause (ref.).

[The past perfect is used (among other possibilities)] when we are reporting our experience up to a point in the past:

I was pleased to meet George. I hadn’t met him before, even though I had met his wife several times.

The time when the door is reached is in the past; the experience that is being reported is found in the past since it must be before the door is reached; therefore, according to this principle the pluperfect is needed.

• By the time he had reached the door, he had remembered the pink diamond.

by the time (MacMillan) 1 used for saying what has already happened at the time that something else happens

• By the time we arrived, the other guests were already there.

The same is true for the second sentence. Here is a reference showing this principle more explicitly: Grammar-Quizzes. The items to be checked in this reference: "past perfect observation", "tense agreement".

EXAMPLES

Moonlight Flitting - He had reached the back door of the lodge, and if he had heard the shouting at least he had paid no attention to it.

First Man West - When Columbus landed on a Caribbean island he thought that he had reached Asia, but we know that he had come less than half-way.

A Harold Bell Wright Trilogy: The Shepherd of the Hills/The - By the time he had reached State Street in the business district, the groceryman had decided that to call for Saxton at that unusual hour would not be wise.

The Missionary: An Indian Tale - Volumes 1 à 3 - He had reached the utmost limits of human temptation and human resistance, and shuddered at the risk he had run,…

Song of the Nile - He had reached the official age of manhood, fourteen, some five years before and even though, according to the elders, he was still 'wet behind the ears', he had already proved himself.

Temple Grove: A Novel - He had reached the steepest incline he'd encountered so far.

Man of Wiles in Popular Arabic Literature - He had, in fact, been looking for ʿAbd al-Wahhab and, although he had reached the furthest parts of Khurasan, he had found no news either of him or of ʿUqba. - Bill stopped for a moment, clutching ice that was numbing both his hands through the logging gloves.

The History of England from the Accession of James II - He had reached his fiftieth year without having sate in the English parliament; and his official experience had been almost entirely acquired at foreign courts. He was justly esteemed one of the first HISTORY or ENGLAND.

Human Cargo - He had reached the end of a legal line he had been crawling along for the past eighteen months: …

Trapped!: The Story of Floyd Collins - He had reached this point several times before, but had always been stopped by a pile of rocks, a terminal breakdown.

Here is a different example, one in which the past is used, and it is to be understood that the action of finding out is consecutive to that of reaching the West Indies; if it had been anterior, the past perfect would have been correct.
Aztecs - He thought he had reached the Indies and he never found out his mistake.

A Story of To-day - whatever was the resolve he had reached in the solitary hours when he had stood so close upon the borders of death, it was unshaken now;