The most important thing about using tenses is, answering the two questions above: How do we use tenses? Why do we have to use these tenses? For example, in the present continuous tense, we can use these tenses when an event is taking place. Or more often we are familiar with the time signal or time marker. Apart from that, you might go to britishlifeskills.com if you want to take the English exams for those who want to acquire the UK visa legally.
The thing to remember after the structure is when you can use the tense. So, all you need to do is make a summary of 16 tenses by writing STRUCTURE and TIME SIGNAL. Create a summary that is simple, interesting, and easy to read. Example time signal for present continuous:
“Diana is reading a book now”.
It means that in this current timeline, when you are reading this sentence, Diana is in the middle of her reading activity. She is not just started, or just finished, but simple in enjoying her reading, right now, at this moment.