Definition / Explanation
In the past simple, we make questions and negative sentences with did. This is different from affirmative sentences, where the main verb often has a past form such as worked or played. After did or didn't, the main verb returns to the base form. This rule is very important because learners often use two past forms together by mistake.
Key Rules
- Use did not / didn't + base verb for negatives.
- Use Did + subject + base verb...? for questions.
- After did/didn't, do not use the past form of the main verb.
- Use the same helper for all subjects: I did, she did, they did.
- Do not use did with the main verb be. Use was/were instead.
Examples
- Did you call him yesterday?
- I didn't understand the question.
- Did she work on Saturday?
- They didn't stay long.
- Did your parents visit you last month?
Common Mistakes
- ❌ Did you called him? -> ✅ Did you call him?
- ❌ She didn't went to work. -> ✅ She didn't go to work.
- ❌ Did he was late? -> ✅ Was he late?
Tips
- If you already have did in the sentence, the main verb should usually be in the base form.