since he has lived in London

[joham]

He has made a lot of friends since he has lived in London.
It is three years since he has lived in London.


question: Does the clause "since he has lived in London" in the two sentences mean the same thing: since he came to live in London?

Thank you very much.

[Niall]

No. It doesn't. Though in most languages it would - not in English!

The first, as you said, means since he came to live in London.
The second, however, means something different. It means since he stopped living in London.

If you are looking for an explaination of this, I will give it to you :P

[joham]

No. It doesn't. Though in most languages it would - not in English!

The first, as you said, means since he came to live in London.
The second, however, means something different. It means since he stopped living in London.

If you are looking for an explaination of this, I will give it to you :P

Thank you very much. Some of us friends have been discussing this problem. And one of my friends who is sure he's very good at English grammar says the two clauses are the same in meaning, and I cannot convince him. So I'm here and have got your kind help. Thank you again!

[Niall]

Point him in this direction:
The second phrase is using a construction of Period of time followed by since followed by Present Perfect (Simple) Action.
As in the example:
It has been half a year since I have played tennis
This means I havn't played tennis for half a year. (Your friend would think it meant that I have been playing tennis non-stop for half a year!).
The same applies in the example:
It has been ten weeks since he has visited me
Which means "he" hasn't visited me for ten weeks.

Hope this helped!

[engee30]

Point him in this direction:
The second phrase is using a construction of Period of time followed by since followed by Present Perfect (Simple) Action.
As in the example:
It has been half a year since I have played tennis
This means I havn't played tennis for half a year. (Your friend would think it meant that I have been playing tennis non-stop for half a year!).
The same applies in the example:
It has been ten weeks since he has visited me
Which means "he" hasn't visited me for ten weeks.

Hope this helped!

Reading your explanations, I seem not to understand one thing - why is it that the Past Simple tense is preferred in such cases, including the adverb last?
It's many years since you (last) visited me.

Is it really possible to use the Present Perfect Simple tense in the since-clause in this case?
I don't get it!

[Niall]

Yes.
It is many years since you have visited me.
You have visited is afterall Present Perfect Simple.

Of course, the use of last instead sounds much better, and much more colloquial, but its good to know both constructions.

[engee30]

Yes.
It is many years since you have visited me.
You have visited is afterall Present Perfect Simple.

Of course, the use of last instead sounds much better, and much more colloquial, but its good to know both constructions.

It is really good to know that!

[riverkid]

He has made a lot of friends since he has lived in London.
It is three years since he has lived in London.


question: Does the clause "since he has lived in London" in the two sentences mean the same thing: since he came to live in London?

Thank you very much.

Actually, this one

He has made a lot of friends since he has lived in London.

sounds a bit strange to me. 'since he has lived in London' could be glossed/read to mean,

"Because he has lived in London", [with 'lived' a now finished event]

with an overall meaning of,

He lived in London in the past and because of something he learned/because of something that happened to him in London, he has been able to make a lot of friends.

"He has made a lot of friends since he has lived in London"

would, to my mind, be clearer as,

He has made a lot of friends since he moved to London.

[Niall]

It is quite accurate indeed to say that it would be clearer as
He has made a lot of friends since he moved to London.

Not only do you not have to decript the confusing tenses of the sentence, it also reads a lot better. :P

[engee30]

Actually, this one

He has made a lot of friends since he has lived in London.

sounds a bit strange to me. 'since he has lived in London' could be glossed/read to mean,

"Because he has lived in London", [with 'lived' a now finished event]

with an overall meaning of,

He lived in London in the past and because of something he learned/because of something that happened to him in London, he has been able to make a lot of friends.

"He has made a lot of friends since he has lived in London"

would, to my mind, be clearer as,

He has made a lot of friends since he moved to London.

The situation demands context again. If he still lives in London, it's absolutely alright to use the Present Perfect Simple in the since-clause; the situation changes significantly if we use the Past Simple tense:

He has made a lot of friends since he has lived in London. (still in London)
= Between the time of his moving to London and the time up to now he has made a lot of friends.

He has made a lot of friends since he lived in London. (not in London any more)
= Between the time of his leaving London and the time up to now he has made a lot of friends.

The same goes for a situation where somebody is still a student, or when they aren't a student any more:

I have made a lot of friends since I have been a student (= since the moment I started my college, and I still attend it).
vs.
I have made a lot of friends since I was a student (= since the moment I finished my college).