Is present tense always perfect tense or can there be imperfect present tense? What about future tense? Is future tense perfect tense or imperfect? Can it be both?
A perfect tense is a tense which describes a finnished action.
Present Perfect tense is (as its name suggests) a perfect tense; it means that this tense describes an action completed in the near past which has its influence on the present situation.
An imperfect tense describes an action which is not completed.
Continuous tenses (also called Progressive) describe unfinnished actions, so they are imperfect ones.