I read that nonfinite verb form end in -ed,-ing or starts with to and another definition where nonfinite verb form show no tense.
But on the other hand, I’ve read there are past and present progressive verb forms. They start with is/are/am and end in -ing for present tense. In past form they start with was/were and end in -ing.
Similar thing for present/past perfect form except it uses different starting words and ends in -ed.
Are these verb phrase which have forms in the past and present, nonfinite?
The verb phrases used in constructing the progressive tenses contain both finite and non-finite verbs.
For example (finite verbs italicized, non-finite verbs bolded):
“I am learning to play the piano.”
“I have never been there before, but I plan to go in the future.”
“He has been studying chemistry for many years.”