In regard to this answer, my question is similar but that answer is not clear. I want to know why we use base form of verb, e.g. 'go' to form the past tense instead of past form such as 'went'?
Question: Did you go to a bank? (Why we use 'go' here, rather than 'went'?)
Answer: I went to a bank.
Am I confusing verb forms with tenses? Please note that I'm not a native speaker so some clarification or reference on this would be helpful.