present perfect

[sardine]

Hello everyone,

I have a question about how to use present perfect.
In my country, we learn that we can't use present perfect with "ago".

That means, can't we say, "I have lived here since five years ago."??

We can say, "since 2000, since last week"... but shouldn't we say since and ago together?

Does it sound strange for you?

Thanks in advance.

[Casiopea]

"5 years ago" functions adverbially, which means it modifies the verb "have lived". Now, present perfect verbs are incompatible with specific dates/time, and that's why [1] below is ungrammatical (*). The phrase '5 years' directly modifies a present perfect verb:

[1] I have lived there *5 years ago.
[2] I have lived there *5 years.

The word 'ago' has nothing to do with anything, really. In example [2] 'ago' is missing and the sentence is still ungrammatical.

If a specific date/time directly modifies a present perfect verb, the result will be ungrammatical, but if we disguise the specific date/time, by putting it inside another phrase, so the verb doesn't "see" it, we get a grammatical result, like this,

[3] I have lived there for 5 years.
[4] I have lived there since 2000.

The phrase '5 years' no longer directly modifying the verb 'have lived'. It's part of (or inside of) 'for. . .'. The entire phrase 'for 5 years' modifies the verb 'have lived'. '5 years' is disguised, or hidden, sort to speak, from the verb's eyes. The same holds true for the phrase 'since 2000'.

Note, [5] and [6] below are ungrammatical. "ago" can't stand on its own ([5]), and "5 years", a noun phrase, doesn't function adverbially on its own ([6]).

[5] I lived there *ago.
[6] I lived there *5 years.

It's a pair:

a long time + ago
3 hours + ago

"ago" comes from agone, which meant gone by:

5 days have gone by = 5 days agone => Modern English: 5 days ago

Hope that helps,

[sardine]

Thank you for your answer.
I have already understood

[1] I have lived there *5 years ago.
is incorrest.
[2] I have lived there *5 years.
is incorrect.
[2] I have lived there for 5 years.
is correct.

In my opinion, for example, (the year) 2000＝five years ago
Therefore, since 2000＝since five years ago


So, can I say, "I've lived here since five years ago."?

Sorry for my poor explanation.

[Casiopea]

In my opinion, for example, (the year) 2000 ＝ five years ago
Therefore, since 2000＝since five years ago. So, can I say, "I've lived here since five years ago"?

"the year 2000" and "5 years ago" do not mean the same thing, so you can equate them in that way. Moreover, "since" and "for" have semantic restrictions.

[1] I have lived here since the year 2000.
[2] I have lived here for *the year 2000.

[3] I have lived here since *5 years ago.
[4] I have lived here for 5 years *ago.

[sardine]

"the year 2000" and "5 years ago" do not mean the same thing
Oh, really? I've never thought about that. In my language, there're little diffrence. So we can't say, [3] I have lived here since *5 years ago.
[/u].

Thank you very much!

[Casiopea]

You're welcome, Sardine.

Oh, really? I've never thought about that. In my language, there're little diffrence. So we can't say, [3] I have lived here since *5 years ago.

Well, English is a different language. Please note, "I have lived here since 5 years ago" is also ungrammatical in English. The symbol * means ungrammatical.