Use the correct tense-forms of the verbs in brackets.
1. You (to know) English well?
2. Ann (not to learn) the poem by heart yet. She still (to learn) it.
3. Last summer I (to visit) Riga. I (to enjoy) my trip very much. Also I (to want) to see Tallinn, I (to go) there this summer if I (to enter) the Institute.
4. "Mr. Brown (to come) an hour ago. He (to wait) for you in the sitting room", said Tom to his sister.
5. When the telephone (to ring) Jack (to have dinner).
6. Where you (to be) all this time? I (not to see) you for ages.

Do you know English well?
(Вопрос о знании языка в настоящем времени → Present Simple.)

Ann has not learned (hasn't learned) the poem by heart yet. She still is learning it.
(«Yet» указывает на Present Perfect, а действие, которое продолжается сейчас, — Present Continuous.)

Last summer I visited Riga. I enjoyed my trip very much. Also I wanted to see Tallinn, I will go there this summer if I enter the Institute.
(Прошлое лето → Past Simple; желание и планы в прошлом → Past Simple; будущее условное предложение: Future Simple + Present Simple после if.)

"Mr. Brown came an hour ago. He is waiting for you in the sitting room", said Tom to his sister.
(«An hour ago» → Past Simple; действие происходит в данный момент → Present Continuous.)

When the telephone rang Jack was having dinner.
(Одно действие прервало другое в процессе: Past Simple + Past Continuous.)

Where have you been all this time? I have not seen you for ages.
(Действия связаны с настоящим моментом и продолжаются до сих пор → Present Perfect.)