Answer:
How quickly has he done it?
Most of the students aren't good.
They used to be in love (at one time).
They invited no one to the party.
Yesterday he said, "I will meet you tomorrow."
Everybody has a cellphone these days, don't they?
Explanation:
Question words (also called interrogative words) are words we use to ask questions. <em>How </em>is one of them.
Negative sentences are usually formed by adding the word <em>not </em>after the auxiliary verb (in the second question - after <em>are</em>).
We use the phrase <em>used to </em>to talk about things in the past which are no longer true. In the third sentence, <em>at one time</em> can be omitted because, if we use <em>used to</em>, it's understood that something happened at one time.
When we're converting passive voice into active voice and don't know who the subject is, we can use <em>they </em>as the subject.
Direct speech quotes someone's words directly - in the exact way they were spoken.
Tag questions are questions we ask to get confirmation. We attach a tag question to the end of a statement, turning the entire statement into a question. If the main clause is positive, the tag question will be negative (and the other way around).
