What is Imperfect, Aorist, Perfect, and Pluperfect Tense ? Examples please.
With the exception of 'perfect', the tenses you cite are either inapplicable to English or use an out-of-date name. May I ask where you found them?
Unlike, say, French, English does not have an 'imperfect' tense, though we do talk of perfective and imperfective interpretations.
There is no 'aorist' tense in English, though some languages, like Turkish for example, do have an aorist tense, as of course does Latin and Greek.
The perfect is a past tense that is analytical rather than inflectional like the preterite tense: cf. "I have been to Bonn" (perfect) ~ "I went to Bonn" (preterite). The perfect tense can combine with the preterite ("I had been to Bonn") and present tense ("I have been to Bonn"), but can also occur in clauses without inflectional tense ("having been to Bonn").
This is an old out-of-date term, now generally replaced by the term 'preterite perfect' (see 'perfect' above).
Note: some people call the 'preterite' the 'simple past tense'.