Since......ago

[Mauro63]

Hi everybody,
I have recently read on the Practical English Usage by Michael Swan the following sentence regarding "ago"

We've been living here since about eight years ago.
i haven't bought any since a week ago.

if i said "for eight years" or "for a week" would it mean the same?

There's a note on the book saying, ..... However, a present perfect tense is used with - since....... Ago ( as with since +any other time expression).

I would appreciate your opinions about this topic.
Thank you .

[bhaisahab]

Hi everybody,
I have recently read on the Practical English Usage by Michael Swan the following sentence regarding "ago"

We've been living here since about eight years ago.
i haven't bought any since a week ago.

if i said "for eight years" or "for a week" would it mean the same?

There's a note on the book saying, ..... However, a present perfect tense is used with - since....... Ago ( as with since +any other time expression).

I would appreciate your opinions about this topic.
Thank you .

"We've been living here for about eight years."
"I haven't bought any for a week."
These have the same meaning as your two original sentences.