The present perfect tense, during+time, indicates a certain period of time, and is often used as a time adverbial in the present perfect tense. The present perfect tense is often followed by time adverbials: such as so far, by now, up to (till) now, for, since, in the past few..., during the last few... etc. We have planted more than two thousand trees by now.

1. It means "during..." and is a preposition. Do not misuse it as a conjunction. Such as:

While he was in Paris, he lived with his friends.

False: During he was in Paris, he lived with his friends.

True: While he was in Paris, he lived with his friends.

True ：During his stay in Paris, he lived with his friends.

2. Both during and for can express a period of time, but there is a difference between them.

(1) During usually indicates when the event occurred (when), while for indicates how long the event lasted (how long). For example:

He was in hospital for six weeks during the summer. He was in hospital for six weeks during the summer.

(2) Both can be followed by time phrases caused by the whole, but usually cannot be followed by time phrases caused by all. Such as:

He lived there all summer.

True: He stayed there for [during] the whole summer.

False: He stayed there for [during] all the summer.

(3) The preposition for can be used before "numeral + time noun" and before phrases such as some time, a long time that generally refer to a period of time, but not during. For example:

He lived here for ten years (for some time). He lived here for ten years (for some time).

3. During and in can both mean "point in time" and are sometimes interchangeable. For example:

I'll be on holiday in [during] August. I will be on holiday in August.

He woke up three times in [during] the night.