"having seen" vs "seeing"

[subhajit123]

Hi there, what's the difference between "having seen" vs "seeing"?

1. John had a knee surgery last year. Having seen him play football, I am very glad.
2. John had a knee surgery last year. Seeing him play football, I am very glad.

 

[Charlie Bernstein]

Hi there, what's the difference between "having seen" vs "seeing"?

1. John had (delete a) knee surgery last year. Having seen him play football, I am very glad.
2. John had (delete a​) knee surgery last year. Seeing him play football, I am very glad.

That's a tricky question.

In casual conversation, they can mean the same thing.

More strictly speaking, the tense of #1 says that you've seen him play in the past, and the tense #2 means you're watching him now.

You can say "a knee operation" but not "a knee surgery." Both "the knee operation" and "the knee surgery" are fine. (That's American English. I don't know about British.)