Which is correct?
This problem is tricky. I would never have been able to solve it without (knowing / having known) other similar problems.
- RPLv 71 month agoFavorite Answer
Having known is best, although the other is acceptable. In addition, "other similar" is a redundancy that can be resolved by removing "other." Similar says it all,
- 1 month ago
I would rewrite the sentences.
This problem is tricky. If I didn't have similar problems, I wouldn't know how to solve it.