The revised sentences are
I. Nobody helped me, did they?
II. Did someone break the vase?
III: He has written some books
IV. They are doing mediation
V. He asked me if I was a student
VI. He didn't speak a word.
This question requires you to transform each sentence based on the instruction given. Let's analyze each case:
A question tag is a phrase added at the end of a question to emphasize it. The general structure of the question tag is auxiliary verb + subject. Moreover, if the first statement is negative the question tag is affirmative and vice versa.
To make a sentence affirmative remove any negative words and adjust other words if necessary.
To use the correct form of a verb consider the context to know if the action is happening, will happen, or is already finished.
Indirect speech implies reporting what another person said, this usually implies a change in the verb, for example, a verb is present changes to past.
In the active voice, the general structure is subject + verb + object or complement.
Learn more about sentences in: https://brainly.com/question/1395561