It was only 5 years ago when I became an engineer.
A friend of mine told me that the when used in above sentence is incorrect and it should be replaced by that is it true ? I checked the ngram and found both of these being in use.
It was only 5 years ago when I became an engineer.
A friend of mine told me that the when used in above sentence is incorrect and it should be replaced by that is it true ? I checked the ngram and found both of these being in use.
The use of that instead of when seems correct in the context of this sentence.
However the grammar checker in my old version of Microsoft Office (set to US English), does not flag the use of the word when.
This could be a case of how the sentence reads. The word when may be acceptable. but that flows better and is the way I would phrase it.
If this was a partial sentence, then the use of when may be acceptable, for example:
"It was only 5 years ago when I became an engineer, but prior to that ...."
It may be acceptable but grammarians insist that ago and when should not come side by side.
It was only five years ago that I became an engineer
It was five years ago that I started speaking English is the preferred form.
I think native speakers use this way.