ago · adverb /əˈgoʊ/
ago
A2 used to refer to a time in the past
Dictionary examples:
He left the house over an hour ago.
We left New York ten years ago.
About five months ago, I got a letter from him.
The dinosaurs died out 65 million years ago.
Learner example:
Two months ago I booked a trip to Malta. (Skills for Life (Entry 2); A2; Russian)
long ago
C1 If something happened long ago, it happened a great amount of time ago.
Dictionary examples:
I think we met once, long ago.
It was not long ago that I last saw him.
Learner example:
Not so long ago, you could ring each Dutch doorbell of your choice at 6 pm and you'd f[i]nd the whole family gathered around the kitchen table, having their supper. (Certificate in Advanced English; C1; Dutch)