Как изменять слова по мременам глаголов по ин яз we(twvite)letterst

We write letters. we are writing letters. we have written letters. we wrote letters. we were writing letters. we had written letters.we shall write letters. we shall be writing letters. we shall have written letters.

Ithink he will take part in this comprtition.  - я думаю, что он примет участие в этом соревновании.