The Perfect Tenses in English
“The three perfect tenses in English are the three verb tenses which show action already completed. (The word perfect literally means “made complete” or “completely done.”)
They are formed by the appropriate tense of the verb to have plus the past participle of the verb.
Present Perfect: I have seen it.
(Present tense of to have plus participle. Action is completed with respect to the present.)Past Perfect: I had seen it.
(Past tense of to have plus participle. Action is completed with respect to the past.)Future Perfect: I will have seen it.
(Future tense of to have plus participle. Action is completed with respect to the future.)
” Source: http://englishplus.com/grammar/00000361.htm
The Imperfect Tense
KTA: The imperfect tense refers to an action that is still going on. It had not been made perfect or completed. It describes a continuing or repeated event or state. The key to the definition of the imperfect tense is that the action has not been completed or made perfect.
The Perfect Tenses in Spanish
https://www.spanishdict.com/guide/spanish-imperfect-tense-forms