I told them I would come back as soon as I _____

Analyze the question

The sentence is: "I told them I would come back as soon as I _."

The main clause, "I told them I would come back," is in the past (reported speech). So the verb in the subordinate clause must agree with this past-tense sequence.

Explain the concept: Sequence of tenses

When the main verb is in the past tense, the verbs in the clauses that follow it usually shift to the past as well.

• Direct speech: "I will come back as soon as I can."
• Reported speech: I told them I would come back as soon as I could.

will → would and can → could

Step-by-step solution

1. "I told them" puts the sentence in the past.
2. "would come back" is the past form of "will come back".
3. The clause "as soon as I ___" must also be in the past form, so can becomes could.
4. Checking the options: • A. should: it suggests obligation, so "as soon as I should" does not fit the meaning. • B. can: it is present tense and breaks the sequence of tenses. • C. could: it is the past form of can and fits the meaning (as soon as I was able to). • D. will: it is future and does not agree with the past-tense main clause.

Answer: C. could

Completed sentence: "I told them I would come back as soon as I could."

Exam tip

In reported speech, shift each verb back one step: will → would, can → could, may → might, is → was. If the first verb is in the past (told, said, promised), look for a past-form answer in the blank.