I'm learning English as a ESL student. In addition, I have never been to English-speaking countries, so I couldn't learn which grammar is no more useful these days. In my memory, I haven't seen any sentences using past continuous tense and future perfect tense in the articles that I read except grammar books. So I wonder these tenses are useful when native users speak or write something or they are just old grammar that few people use.
Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.