Identify the segment in the sentence which contains the grammatical error.
You could find our house easily, didn’t you?

Correct option is A

The error lies in the question tag – “didn’t you?”.

Correct structure:

• When a sentence uses "could" as a modal auxiliary verb, the question tag must repeat the same auxiliary in the negative or positive form depending on the main clause.

• Rule:

  • Positive main clause → Negative question tag

    • You could help her, couldn’t you?

  • Negative main clause → Positive question tag

    • You couldn’t do it, could you?

Grammar Rule:

Modal Auxiliary + Base Verb structure requires repetition of the same modal in the question tag.

• Example:

  • She can swim, can’t she?

  • They will come, won’t they?