Word order: six weeks ago
Ago follows an expression of time.
I met her six weeks ago. (NOT …
ago six weeks.)
a long time ago
An expression with ago refers to a finished time, and is normally used with a past tense, not a present perfect.
She phoned a few minutes ago. (NOT
She has phoned... )
Where’s Mike? ~ He was working outside ten minutes ago.
The difference between ago and for:
Ago says how long before the present something happened; for (with a past
tense) says how long it lasted.
He died three years ago. (= three years before now)
He died for three years. OR .. for three years ago.)
He was ill for three years before he died. (= His illness lasted three years.)
We use ago with a past tense and a time expression to ‘count back’ from the
present; to say how long before now something happened. We can use before in the same way (with past perfect tense) to count back
from a past moment.
I met that woman in Scotland three years ago.
three years before/ before three years.)
When we got talking, I found out that I had been at school with her husband ten years before. (NOT …
ten years ago.)
Ago and before