I am not sure what you meant to write. I have tried below to give a possible different way of phrasing this.
The first exercise
I learned how to tell time in English. The word "it" is difficult. I don't understand how "it" is used in a sentence.
Русскоговорящему всё понятно))
Something like that:
The begining/First of all.
I'm learning English tenses. It's hard. I can't understand how is it possible to understand them.
{the first
I learn times for english.. the it is difficult..i dont't understand as it is possible to understand?}
First of all!
I'm learning English tenses. It's hard. I can't understand how is it possible to understand them