The past perfect

past

If you have studied other languages, you may have found this tense referred to as the pluperfect and it sometimes called that in English grammar, too. Here, however, we'll use the usual term for it, the past perfect.

What is the past perfect?

The past perfect (like all perfect forms) is a relational rather than absolute time marker. That means that the tense is used to link actions or states in relation to each other, not set them at a particular time.

The past perfect tense refers to the past in the past or the past before the past. For example:

She had visited France often before then
She had met him before and knew his reputation.
They had spent the afternoon skiing and were looking forward to a rest.

A simple time line can make it clearer:

past perfect time line

In fact, as sentence 1 above indicates, the past perfect often occurs without the past simple. For example,

He had arrived before me.
Before lunch they had played cards.

Note, however, that some other past event or state is always implied in these circumstances. In sentence 4, that implication is that I also arrived and in sentence 5, there is a clear implication that they ate lunch after they played cards.

What does the past perfect do?

Two things (basically):

To refer to the time before the past:
He had met the man before and recognised him
The horse had been raced hard and was exhausted
etc.
To distance the speaker from an event or state in the present:
I had hoped I would see you
I had meant to mention it

When is the past perfect NOT used?

Consider these six sentences and the verbs in black:

Simple	Perfect
The rain was heavier than he expected. I couldn't light it because I lost the matches. I came after the match finished.	The rain was heavier than he had expected. I couldn't light it because I had lost the matches. I came home after the match had finished.

On the left are the simple past forms of the verbs (expected, lost, finished) and on the right the past perfect forms (had expected, had lost, had finished).
What do you detect? Click here when you have an answer.

There isn't much difference in meaning between sentences 1 and A or between sentences 3 and C and there are two different reasons for that:

The nature of the verb expect. Clearly, expecting precedes an even or state so we know which one came first. The use of the past perfect here is, therefore, unnecessary.
The presence of the word after in sentences 3 and C also mean that the past perfect form is not needed. The word tells us explicitly what came first.

However, in sentences 2 and B, there is a difference. The causal effect of the conjunction because needs explaining so the hearer/reader knows which event occurred first. Most people find sentence 2 unacceptable.

The general rule is, therefore, that when the two events are spoken of in the order in which they occurred and without adverbials such as by then, before, up till then, just, already etc., we do not need to use the past perfect form. So we get:
I went home and had dinner
Here we have two events spoken of in the order they occurred so no past perfect tense is needed.
He lived for 20 years in France and then returned to England
Here we have a state and an event a) spoken of in the order they occurred and b) containing a time adverb (then) so no past perfect form is needed.

When should we use the past perfect?

When events or states are mentioned out of order:: Speakers and writers will often reverse the ordering of events to emphasise one of them.
It's fine to have
    He lived for 20 years in France and retired to England
using two simple past forms but if we reverse the order, the past perfect is usually necessary:
    He returned to England. He had lived in France for 20 years or
    He returned to England after he had lived in France or
    Before he returned to England he had lived in France
etc.
When we have a when-clause referring to a later event:: It's fine to have
    When he retired he went to England
because the events happened at the same time but when they don't, we usually need the past perfect to avoid ambiguity. Compare:
    I made tea when they arrived
with
    I had made tea when they arrived
When the time is not specified:: She had never seen him before that night
They hadn't tried whisky before they went to Scotland
(*She never saw him before that night and *They didn't try whisky before they went to Scotland are both wrong.)
In subordinating clauses:: Especially with causal relationships, the past perfect is commonly used (although two past simple tenses are often possible)
    I made tea because they had arrived
    I didn't go because I had lost my ticket
But we can also have, e.g.,
    I arrived late because the car broke down on the way
where the ordering and causality is obvious.
The rule of thumb here is that it is never wrong to use the past perfect in these types of sentences.

the past perfect progressive

The past perfect progressive and simple forms are different in exactly the same way that the present perfect progressive differs from the present perfect simple. (See the guide to aspect and the guide to the present perfect for more.) In brief, the progressive form emphasises the activity itself rather than the outcome.
Compare these and then click here for some comments:

By the time I got there, she had succeeded in repairing the computer.
By the time I got there she had been trying to repair the computer for hours.
He had been gaining rapidly on the leader when the race finished.
He had gained rapidly on the leader and finished second.

In this sentence, the outcome (success) is emphasised. We cannot say she had been succeeding because success implies an outcome.
In this sentence, the trying is emphasised and the outcome is less important (in fact, there probably wasn't one).
In this sentence, the focus is on the gaining not the outcome (again, the outcome was probably negative).
In this, the outcome (he finished second) is emphasised.

A second but related difference is between:
She had been writing a letter but was unhappy with the wording
action incomplete and may have been resumed and
She had written a letter but was unhappy with the wording
action complete but with relevance to the second past event.

Using the past perfect progressive to distance oneself and sound tentative as in, e.g.,
I had been hoping you might help
makes the speaker sound very diffident and polite indeed.

The past perfect in reported / indirect speech

Briefly, the past perfect is often used when we report something said in the past tense after the time of speaking. So, for example
"I bought it in London"
is reported as
She said she had bought it in London.
However, if the object in question lies before us, the past perfect is not necessary.
See the guide to reported/indirect speech for more on this.