v The Present Perfect is used:
1) to express an action which took place before the present moment, when the speaker’s aim is to emphasize the present result of this action;
e.g. My friend hasn’t come yet. Мій друг ще не приїхав.
2) to express an action which began before the present moment and continued up to it. In this case the preposition formostly used to indicate the period of duration. The starting point of the action is indicated by means of the word since.
e.g. I have known her for 10 years. Я знаю її вже десять років.
v The Past Perfect Tense is used:
1) to express an action which took place before another past action or before a definite moment in the past indicated by such expressions as by 5 o’clock, by that time, by Saturday, by the 15th of December, by the end of the year …
e.g. I had done my work by 8 o’clock. Я зробив роботу до 8 години.
2) to express an action which began before a definite moment in the past and continued up to that moment.
e.g. I had not received the telegram Коли він приїхав, ми when he arrived . ще не одержали
. телеграми.
v The Future Perfect Tense is used:
to express an action completed before a definite future moment or before the beginning of another future action.
e.g. He’ll have read the story by the Він прочитає time you come back оповідання, поки ти
. повернешся.