Which verb tense indicates continuing action: Future, Progressive, Present, or Past perfect?
All Progressive (Continuous) tenses.
Present (Simple) tense indicates a repeating action. It can be recognized by time words like usually, every day, often and so on.
Future (Simple) indicates a future event. We use this tense if we decide to do something at the time of speaking. An example could be:
Someone is knocking the door. I will open it.
Speaker could not decide to open the door before he/she heard someone knocking so the decision was made at the time of speaking.
Past Perfect (Simple) indicates which of 2 past events took place earlier.
Tom had done his homework before he went out to play football.
All progressive tenses (except Present Progressive) indicate that the described actions took a longer time than ones described by Simple tenses.