Нужно поставить время и объяснить. 1. he’s very tired. he (to try) to translate these articles all the morning. 2. if he (to be) cleverer and more persistent he (to receive) a better mark for the test. 3. margie just called and said she would be here at 8 o’clock. by the time she gets here, we (to wait) for her for two hours. 4. the boy (to play) the violin for already two hours when his parents came back. 5. if he (to book) tickets beforehand, he (to get) much better seats.

Попробую...(но я не уверен)
1. was trying
2. will be , will receive / если же вы время проходите , то were , would have received 
3. were waiting
4. had been playing
5. had booked , got

1. He’s very tired. He had been trying to translate these articles all the morning.
(Past Perfect Continuous)

2. If he would be cleverer and more persistent he would receive a better mark for the test. (Present Future in the Past)

3. Margie just called and said she would be here at 8 o’clock. By the time she gets here, we have waited for her for two hours.
(Present Perfect) 

4. The boy had been playing the violin for already two hours when his parents came back.
(Past Perfect Continuous)

5. If he will book tickets beforehand, he will get much better seats.
(Future Simple)  

Напиши, что было правильно, а что нет.