There is no such thing as perfect tense in Ukrainian :) We have only one past tense. But it may have two aspects: finished and unfinished. They sometimes overlap with the English perfect tense by meaning, but not always, very often they can be interchanged as the Ukrainian aspect carries slightly different information in it. I can provide more details if anyone wants, just reply to this comment.
It depends on which source you follow. It is a subject of much discussion. In general, linguists say English has one past tense and four aspects, but in schools it is taught that there are four past tenses. This is a generalisation. The definitions are the same, it's just the labelling that is different.
okay great..it was my attempt to render a poetic English phrase the road less traveled