Here is a good overview of the past perfect. https://www.ef.com/ca/english-resources/english-grammar/past-perfect-tense/ As a related topic, Su.Ki. gave an excellent overview of the simple past and present perfect. https://www.italki.com/question/463361 Here is some general information : https://www.ef.com/english-resources/english-grammar/present-perfect-vs-simple-past/ https://www.ef.com/english-resources/english-grammar/simple-past-tense/ https://www.ef.com/english-resources/english-grammar/present-perfect/

Thank you Phillip! Is the form of the past perfect = (S + have/has + pp) or (S + had + pp) ?

Hmmmm….. The simple past is common for conversation, and the past perfect is more often used when the action is complete and did not take a long time. Also used more formally. The simple past: I did this, we did that, then we did other things, and then we..... etc. The past perfect: I have done this, I have completed this and then we have gone out … I'm sorry: I don't know much grammar of my language.