When should I use Had modified - OR - Modified.

[Sureshvemuri]

When should I use - Had + Past Participle
Had + Modified
Ex: I had modified the file on last Monday
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Just Simple Past tense.
Ex: I modified the file on last Monday

Assume that, here, I am telling about ONE action only.
I don;t tell two actions in a row.
Ex: I had modified the file and uploaded to Server(This is not what I would tell).

[Yankee]

Hi Sureshvemuri

Very generally speaking, you will find the past perfect form in sentences about the past which have two clauses, and the action in one of the clauses preceded the action in the other clause.

One example would be so-called Type 3 IF-sentences:

- If Jim had not resigned, his boss would have fired him.

i.e. Jim resigned before his boss could fire him.

.
Here is another example. The past perfect tells you that 'engulfed' happened first:

- By the time I called the fire department, the flames had completely engulfed the house.

.
The past perfect is also used in 'wish' sentences that refer to the past (i.e. when you express dissatisfaction with a past action or event):

- I wish I hadn't said that to him.

[Sureshvemuri]

Thanks for your time and reply.