Put the adverbs of frequency in their proper place. 1. We are late for school (sometimes).
2. Is he so nervous (always)?
3. I have classes in the evening (never).​

Sure, I'd be happy to help! Here are the correct placements for the adverbs of frequency in the given sentences:

1. We are sometimes late for school.
Explanation: The adverb "sometimes" describes the frequency of being late for school. It shows that it happens occasionally but not all the time.

2. Is he always so nervous?
Explanation: The adverb "always" describes the frequency of being nervous. It indicates that he is nervous all the time, without exception.

3. I never have classes in the evening.
Explanation: The adverb "never" describes the frequency of having classes in the evening. It means that there are no classes scheduled for the evenings at all.

To solve this exercise, it's important to understand the meaning and usage of each adverb of frequency:

- Always: It means something happens every time without exception.
- Sometimes: It means something happens occasionally, but not all the time.
- Never: It means something does not happen at any time or under any circumstances.

By placing these adverbs in the appropriate positions within the sentences, we can accurately convey the frequency of the actions or situations described.