Question

What was the problem? Why ................................ leave early?

• A. have you to
• B. did you have to
• C. must you
• D. you had to

Hint:

Past obligation = \textbf{had to}. In questions: \textbf{did + subject + have to}.

Answer 1

The Correct Option is B

Step 1 (Tense and meaning): The situation is in the {past} (“What was the problem?”). We need past obligation $\Rightarrow$ had to.
Step 2 (Question form): In past simple questions, use {did + subject + base verb}. Hence did you have to leave.
Step 3 (Reject): (a) unnatural modal pattern; (c) present-time necessity; (d) lacks inversion for a question.