before I have been

[CarloSsS]

Is the following structure acceptable? What worries me is the usage of present perfect with the preposition "before". On the other hand, I cannot come up with anything better that would convey the same meaning.

We need to leave before we have been here too long.
I have to finish my homework before I have been here for two hours.

Are both of the sentences natural?

 

[emsr2d2]

Is the following structure acceptable? What worries me is the usage of present perfect with the preposition "before". On the other hand, I cannot come up with anything better that would convey the same meaning.

We need to leave before we have been here too long.
I have to finish my homework before I have been here for two hours.

Are both of the sentences natural?

The first is fine. However, if you are talking about needing to leave before your host is bored with your presence, we have a set phrase for that - "We need to leave before we outstay our welcome".

I would be inclined to reword the second completely to "I have to finish my homework within two hours of arriving here".

 

[CarloSsS]

That's interesting. They are essentially the same structure, yet the latter is unnatural? Why is that? Is it because of the time adverbial (two hours)? Can anybody think of an example with "before I have been here for xxx" that would sound natural?

 

[5jj]

They are essentially the same structure, yet the latter is unnatural?

That's rather a leap.

 

[CarloSsS]

That's rather a leap.

I see, so the latter could be used?

 

[5jj]

It's possible.