Complete the following sentence by using a suitable question tag: I c…

The correct answer is Option (4) → can't I?

Question tags:

• A positive statement takes a negative tag, and a negative statement takes a positive tag.
• The tag is made of:
  • The helping verb of the statement.
  • A pronoun for the subject of the statement.
• This sentence: "I can do it for you" is positive, its helping verb is can and its subject is I, so the tag is can't I?

Complete sentence: I can do it for you, can't I?

Why the Other Options are Incorrect?

Option 1: can't you? — Incorrect. "You" is the object (for you). The tag must repeat the subject "I".

Option 2: can't he? — Incorrect. No "he" appears in the sentence. The subject is I.

Option 3: aren't you? — Incorrect. It uses the wrong helping verb (are instead of can) and the wrong pronoun.

Contrast: the tag repeats the subject of the statement ("I"), not the object ("you").