The English verb tense system can be really intimidating for learners. The different verb tenses and aspects really are tricky, but it can be difficult even to get an answer to a simple question: how many verb tenses are there in English?
The answer that we think is most helpful for English learners is that there are 12 verb forms (more precisely, tense/aspect combinations).
One answer that you will see sometimes is that there are 16 tenses. This response includes the 12 tense/aspect combinations mentioned above, as well as future-in-the-past constructions:
Future in the Past
Future Continuous in the Past
Future Perfect in the Past
Future Perfect Continuous in the Past