when he lived in London

[navi tasan]

1-I corresponded with him for three years when he lived in London.

2-I corresponded with him for three years, when he lived in London.


Is there a difference between the meanings of 1 and 2?

I think in 1 the three-year period in question falls within the period during which he lived in London. So he lived in London for more than three years.

I think in 2 the phrase 'when he lived in London' is either an afterthought (in which case the sentence would mean the same as 1) or is in apposition to 'three years'. In this case, he would have lived in London for three years and I would have corresponded with him in this period.

Gratefully,
Navi.

 

[probus]

A recent book "Eats, shoots and leaves" showed how misplaced punctuation can obscure meaning.

But for the most part the influence of commas on meaning is so slight as to be negligible. There is no difference between your 1 and 2. .

 

[JMurray]

not a teacher

As probus says, the two sentences give us the same information.
The correspondence went on for three years. During the correspondence your friend lived in London. He may have lived there longer, we aren't told.

If you want to indicate that your friend lived in London only during those three years, this is one way to express that.
"I corresponded with him for the three years that he lived in London".