НУЖНО

1. I have done all I could to help him.2. He agreed to help us.3. What makes you look like that?4. To invite friends and to go with them for a walk was his favorite entertainment.5. The next evening I went to see his house.6. The old woman's favorite occupation is to watch the children play.7. I am too busy to go there more than once a week.8. This is a good place to rest.

Exercise 3. Fill in the blanks with the particle to wherever necessary:

1. I want — sing the new song, but I cannot — do it, because I have no ear for music.2. Can't you — make your boy — prepare his lessons well?!3. She wanted me — go there immediately.4. You may — do it when you like; only remember that this is — be done well.5. We asked him — tell us the story in details.6. He watched the old man — walk slowly uphill.7. I never meant — offend you.8. Let her — play as long as she wants.

Exercise 3. Fill in the blanks with the particle "to" wherever necessary:

1. I want TO sing the new song, but I cannot TO do it, because I have no ear for music.

In this sentence, the particle "to" is used after the verb "want" and before the infinitive verb "sing." It is necessary to show the intention or desire to perform the action of singing.

2. Can't you TO make your boy TO prepare his lessons well?!

Here, the particle "to" is used after the verb "make" and before the infinitive verb "prepare." It is necessary to show the action of making someone else do something.

3. She wanted me TO go there immediately.

In this sentence, the particle "to" is used after the verb "wanted" and before the infinitive verb "go." It is necessary to show the intention or desire for someone to perform the action of going.

4. You may TO do it when you like; only remember that this is TO be done well.

Here, the particle "to" is used after the verbs "may" and "is" to link them with the infinitive verbs "do" and "be" respectively. It is necessary to show permission in the case of "may" and obligation in the case of "is."

5. We asked him TO tell us the story in details.

In this sentence, the particle "to" is used after the verb "asked" and before the infinitive verb "tell." It is necessary to show the action of asking someone to perform the action of telling.

6. He watched the old man TO walk slowly uphill.

Here, the particle "to" is used after the verb "watched" and before the infinitive verb "walk." It is necessary to show the action being observed or watched.

7. I never meant TO offend you.

In this sentence, the particle "to" is used after the verb "meant" and before the infinitive verb "offend." It is necessary to show the intention or purpose of the action being discussed.

8. Let her TO play as long as she wants.

Here, the particle "to" is used after the verb "let" and before the infinitive verb "play." It is necessary to show permission or allowance for the action being discussed.

The particle "to" is used in these sentences to connect the main verbs with the following infinitive verbs, indicating the intention, desire, permission, obligation, or observation associated with the action being discussed. It is important to pay attention to the correct usage of the particle "to" in order to form grammatically correct and meaningful sentences.