Present simple - "They often help us" Perfect continuous - подразделяются на : present perfect continuous - "I have been working". past p.c. -"I had been working". future p.c. -"He will have been reading a book for two hours when I come."(Эта форма употребляется крайне редко).
Perfect continuous - подразделяются на :
present perfect continuous - "I have been working".
past p.c. -"I had been working".
future p.c. -"He will have been reading a book for two hours when I come."(Эта форма употребляется крайне редко).