1.
The first question is about the tense we should use after "as soon as". In a sentence such as this:
I had left when the phone rang.
you need to use the past perfect in the second clause to show which action came first and which – second. However, when you use “as soon as”, the sequence is clear and it is normally a matter of preference which one to use, so both your examples will be correct. In American English the preference would normally be past simple. The past perfect would emphasize the fact that one action was complete before the other one occurred. (an explanation given in Grammar for Teachers by Andrea DeCapua)
2.
In the second pair of examples they are both correct again. It is unnecessary to use past perfect because the time is mentioned and the sequence of events is clear. Also, the actions are described in the order in which they occurred. You can use the past perfect if you want, to emphasize that one was before the other.
3.
The third question was about the sentence
He said that the moment he first met her, he felt something special and began to keep a diary.
The actual words the man said must have been:
"The moment I first met her, I felt something special and began to keep a diary."
When you report his words and begin with “He said”, the entire phrase shifts one tense back and becomes:
He said that the moment he had first met her, he had felt something special and had begun to keep a diary.
Although this is the grammatically correct sentence, it is very common that the past simple does not become past perfect in indirect speech. When reporting, native speakers tend to make present tenses past ("I am studying" - "She said she was studying") but very often do not care to make the past tenses perfect, as grammar books always teach us we should.
That is what makes both these sentences correct: "He said that the moment he first met her, he felt something special and began to keep a diary." and “He said that the moment he had first met her, he had felt something special and had begun to keep a diary.” (have a look at the end of this page)
I gave him the money is simple past. You can use it to specify something that happened in the past: you can also specify when it happened, either exactly:
I gave him the money at 6pm
or approximately:
I gave him the money this evening
I gave him the money at about 6
I gave him the money by 6pm.
or not at all:
Yes, I gave him the money.
I had given him the money is past perfect simple. We use this when we are talking about something that had already happened before some event or action in the past. The event isn't usually a specific time: it is a part of the story, for example:
I had given him the money before I got your message
I had already given him the money, but he kept on shouting at me
Here is some more information about simple past and past perfect.
The first sentence, using simple past, is the idiomatic way of saying this. The second sentence doesn't sound right, because after you have said it I am waiting for the event that it happened before: I am not impressed by by 6pm: I want to know what happened next!
The second pair of questions present a different problem.
By 5 PM I gave him the book.
By 5 PM I had given him the book.
Starting with by 5 pm makes these sentences look odd on their own: the seem to need a clause before or after them, for example:
I was working all day, and by 5pm I had given him the book.
The deadline was 6pm, but by 5pm I had given him the book.
By 5pm I had given him the book, and then I went home.
Best Answer
Present perfect I have given is a good way to express and action that was completed in the past but has a lasting consequence. It is ideal for this situation because the other person still has your card. Likewise, has used emphasises that the book is still issued.
For the other three verbs, simple past is fine, as there is no particular need to emphasise the lasting consequence:
I have given my library card to someone in class but i don't seem to recall to whom I gave my card... According to information that I received from library, someone has used it to issue x-book and the date to submit the book was 1st Feb.
to whom I gave my card is grammatically correct, but very formal: most people would say, and many would write who I gave my card to. Also, you should probably use return rather than submit. You submit something for publication: you return something that somebody lent to you.
You would not use past perfect unless you want to describe what happened before some reference event in the past. For example, if you were reminiscing with a friend about your university days and you say: