John should be through with his work, … ?

Analyze the question: This tests question tags. The tag must match the auxiliary (helper) verb in the main clause, and it must be the opposite in polarity (positive statement gives negative tag, and vice versa). It must also use the correct pronoun.

Concept:

• Positive statement → negative tag: "She can swim, can't she?"
• The tag repeats the same auxiliary verb as the statement.
• The pronoun in the tag matches the subject (John → he).

Solution:

1. The statement is "John should be through with his work." The auxiliary verb is should, and the statement is positive.
2. The tag must therefore be negative and use should: shouldn't.
3. The subject is John, so the pronoun is he.
4. The tag is shouldn't he?

Checking the other options:

• A. can't he: wrong auxiliary, since the sentence uses should, not can.
• B. didn't he: wrong auxiliary, since did is for past simple statements with no auxiliary.
• D. isn't it: wrong pronoun (it instead of he) and wrong auxiliary.

The correct sentence is: "John should be through with his work, shouldn't he?"

Tip: For question tags, look for the helper verb (is, can, should, will, has, etc.), flip positive to negative or negative to positive, and repeat that same verb with the matching pronoun. If there is no helper verb, use do/does/did.