Question

the man standing at the corner knows me. gerund or participle​

Answer 1

Answer:

Standing is a present participle which is:

grammar: a verb form that ends in “-ing” and that is used with “be” to refer to action that is happening at the time of speaking or a time spoken of

If you put back the omitted relative pronoun and the verb "be", the sentence will be:

The man who is standing over there is a friend of mine.

The man is standing at the time of speaking. And "standing" is post-modifying the subject when whiz-deletion occurs.

Present or past participles are usually used as an adjective pre-modifying or post-modifying a noun or noun phrase.