. Use the appropriate forms of the verbs in brackets to complete the sentences. 1) It (rain) since morning. When will it stop raining? 2) Nick (go) to the park now. 3) If I (see) him, I (tell) him about their letters. 4) When my friend (come) to see me, I (do) my homework. 5) Alex (meet) his brother two hours ago. 6) I did not know what she (speak) about.

1) It has been raining since morning. When will it stop raining?
The correct verb form to use in this sentence is "has been raining" which is the present perfect continuous tense. This tense is used to express an action that started in the past and is still ongoing. In this case, the action of raining started in the morning and is still happening. The question "When will it stop raining?" indicates that the speaker wants to know when the action will end.

2) Nick is going to the park now.
The correct verb form to use in this sentence is "is going" which is the present continuous tense. This tense is used to describe an action that is happening right now or in the near future. In this case, Nick is currently in the process of going to the park.

3) If I see him, I will tell him about their letters.
The correct verb forms to use in this sentence are "see" (simple present tense) and "will tell" (simple future tense). The conditional sentence "If I see him" indicates a possible condition, and the second part of the sentence "I will tell him about their letters" expresses the result or action that will happen if the condition is fulfilled. In this case, the speaker is saying that if they see this person, they will inform them about the letters.

4) When my friend comes to see me, I will do my homework.
The correct verb forms to use in this sentence are "comes" (simple present tense) and "will do" (simple future tense). The time conjunction "When" indicates that the action of the friend coming to see the speaker is a future event. The second part of the sentence "I will do my homework" expresses what the speaker will do when the friend arrives.

5) Alex met his brother two hours ago.
The correct verb form to use in this sentence is "met" which is the simple past tense. This tense is used to describe a completed action in the past. In this case, Alex met his brother two hours ago and the action has already been finished.

6) I did not know what she was speaking about.
The correct verb forms to use in this sentence are "did not know" (simple past tense) and "was speaking" (past continuous tense). The first part of the sentence "I did not know" expresses a negative statement about the speaker's lack of knowledge in the past. The second part of the sentence "she was speaking about" describes the ongoing action in the past.