When did he ... ?

Let's figure this out together!

• The question is: "When did he ... ?" This implies we're talking about an action that happened in the past.
• We need to choose the correct past tense verb.
• Let's look at the options:
  • 'work' is the base form (present tense for most subjects).
  • 'worked' is the simple past tense form.
  • 'works' is the third-person singular present tense form.
• Since the question starts with "When did he...?", it's asking about a past event. The auxiliary verb "did" already indicates the past tense, so the main verb should be in its base form. Therefore, "work" is the correct choice.

Ответ: work