Ron has a good way of checking the difference between a past verb and a participle, but it looks like he made a typo:
let's say you have "X VERBed", and you're wondering whether "VERBed" is a participle or a past-tense verb.
* if you can answer "did X VERB?" with a yes, then it's a past tense verb.
* if you can answer "did someone/something VERB X?" with a yes,
then it's a participle.
examples:
the speaker dedicated her speech to her late father
"did the speaker dedicate something?" --> yes
"did someone dedicate the speaker?" --> no
hence, past tense verb
the speech dedicated to Mr. Smith was very long
"did the speech dedicate something?" --> no
"did someone dedicate the speech?" --> yes
hence, participle
I am still not able to understand difference between participle (related) vs verb (resembled).
I suggest you check the meaning of these words in a good dictionary:
https://www.lexico.com/en/definition/resembleIs "resembled" always used as verb in GMAT ?
I can't think of an example in which 'resemble' would be used as a participle. This is because resemble can only be used as an active verb: you can resemble something or someone, but
you can't be resembled by them. Check the meaning and some examples and this might be clearer.