Do, Does, Did: Rules, Examples and Common Mistakes
Do, does and did are forms of the verb to do. They have two jobs. As helping (auxiliary) verbs they help us make negatives and questions in the simple present and simple past (I don’t know. Does he know?). As main verbs they mean “perform” or “carry out” (She does her homework).
Use do with I, you, we, they and plural nouns, does with he, she, it and singular nouns, and did for the past with every subject. The most important rule is that after do, does or did used as a helping verb, the main verb is always in its base form: Does he go? not Does he goes?; Did you go? not Did you went?
Do, Does and Did with Different Subjects
| Subject | Present | Past | Example |
|---|---|---|---|
| I | do | did | I do not like tea. / I did not like it. |
| You | do | did | Do you know him? / Did you know him? |
| He / She / It | does | did | Does she know? / Did she know? |
| We / They | do | did | Do they play? / Did they play? |
| Singular noun (Meena, the bus) | does | did | Does Meena sing? |
| Plural noun (the boys) | do | did | Do the boys sing? |
Use do/does for the simple present and did for the simple past. Whenever do, does or did is a helping verb, the main verb that follows is in the base form (the plain form, without -s, -ed or -ing).
Do, Does, Did as Helping Verbs
1. Negative sentences
Add not after do, does or did, and then the base form of the main verb. The short forms are don’t, doesn’t and didn’t.
Subject + do/does/did + not + base verb + rest of the sentence
✅ I don’t eat meat.
✅ She doesn’t live in Bengaluru.
✅ We didn’t watch the match yesterday.
❌ He doesn’t likes coffee. → ✅ He doesn’t like coffee.
❌ They didn’t went to school. → ✅ They didn’t go to school.
2. Yes/No questions
Put do, does or did before the subject, then use the base form of the main verb.
Do/Does/Did + subject + base verb + rest of the sentence?
✅ Do you speak Tamil?
✅ Does your brother play cricket?
✅ Did the bus arrive on time?
❌ Does he goes to college? → ✅ Does he go to college?
❌ Did you saw the film? → ✅ Did you see the film?
3. Wh- questions
Put the question word first, then do/does/did, then the subject and base verb.
✅ Where do you live?
✅ What does this word mean?
✅ Why did she leave early?
✅ How often do they visit their grandparents?
When the question word is the subject of the sentence, do not use do/does/did.
✅ Who broke the window? (not "Who did break")
✅ What happened yesterday?
✅ Who lives next door?
But when the question word is the object, use it: ✅ Who did you meet?
For more on questions and negatives, see Forming Questions in English: The Complete Guide and Negative Sentences in English: Rules and Examples.
Which tense decides between do/does and did?
The helping verb carries the tense, so the main verb does not change. Compare:
✅ She works in a bank. → She doesn’t work in a bank. → Does she work in a bank?
✅ She worked in a bank. → She didn’t work in a bank. → Did she work in a bank?
Read how these tenses work in Simple Present Tense: Rules, Formula and Examples and Simple Past Tense: Usage, Structure, and Examples.
Short Answers
When someone asks a yes/no question with do, does or did, we answer with the same helping verb, without repeating the main verb.
| Question | Yes | No |
|---|---|---|
| Do you like mangoes? | Yes, I do. | No, I don’t. |
| Does she work here? | Yes, she does. | No, she doesn’t. |
| Do they live in Delhi? | Yes, they do. | No, they don’t. |
| Did he call you? | Yes, he did. | No, he didn’t. |
Do, Does, Did as Main Verbs
When do is the main verb, it means “perform”, “carry out” or “work on”. It is common in phrases such as do homework, do the dishes, do exercise, do business and do a course.
✅ I do my homework every evening.
✅ My mother does yoga in the morning.
✅ He did a computer course last year.
✅ What do you do? (The first do is a helping verb, the second is the main verb.)
When the main verb is do, the negative and question also need a helping verb do:
✅ She doesn’t do her homework on time.
✅ Did you do the exercise?
✅ What did you do on Sunday?
We do work, tasks and activities (do homework, do the laundry, do a project). We make things that did not exist before (make tea, make a plan, make a mistake).
Do, Does, Did for Emphasis
In a positive sentence we can put do, does or did before the base verb to give extra stress. It is used to show that something is really true, to disagree politely, or to persuade someone. In speech, we stress the helping verb.
✅ I do like your new haircut! (I really like it.)
✅ She does sing well, but she never performs.
✅ You said I didn’t call. But I did call you!
✅ Do come in and sit down. (a polite, warm invitation)
✅ Do be careful on the road. (a strong request)
Notice that the main verb stays in the base form, even with does or did: ✅ She does sing well. ❌ She does sings well.
When NOT to Use Do, Does or Did
1. With the verb "to be" (am, is, are, was, were)
In statements and questions, be makes its own negatives and questions. (The only common exceptions are orders such as Don’t be late and the emphatic Do be careful.)
❌ Do you are ready? → ✅ Are you ready?
❌ He doesn’t is late. → ✅ He isn’t late.
Learn the forms in Use of Is, Am, Are, Was, Were.
2. With modal verbs (can, will, should, must)
❌ He doesn’t can swim. → ✅ He can’t swim.
❌ Do you will come? → ✅ Will you come?
Modal verbs make their own negatives and questions. See Modal Verbs and Auxiliary Verbs.
3. When another helping verb is already there
Do not use do/does/did with the present perfect or the continuous tenses. ❌ Did you have eaten? ✅ Have you eaten?
Common Mistakes with Do, Does, Did
❌ Does he goes there? → ✅ Does he go there?
❌ Did you went to the market? → ✅ Did you go to the market?
❌ She don’t like spicy food. → ✅ She doesn’t like spicy food.
❌ They doesn’t know the answer. → ✅ They don’t know the answer.
❌ I didn’t saw him. → ✅ I didn’t see him.
❌ Do she study here? → ✅ Does she study here?
❌ Where you live? → ✅ Where do you live?
❌ Why he didn’t come? → ✅ Why didn’t he come?
Only one verb carries the tense. If does or did already shows the tense, the main verb goes back to its base form.
This is one of the most common errors in the tense mistakes Indian learners make.
Practise What You Learnt
Practise helping verbs with the Helping Verbs (Auxiliary Verbs) Worksheet with Answers. You can also check your level with the free level test.
✍️ Quick Practice — Do, Does, Did
- ___ your sister play the guitar? (do/does/did, present)
- We ___ not watch TV last night. (do/does/did)
- My parents ___ not eat out very often. (do/does/did, present)
- What time ___ the shop open? (do/does, present)
- Correct the error: "Did you went to the party?"
- Correct the error: "He doesn’t likes mathematics."
- Make this negative: "They watched the film."
- Make this a question: "Ananya lives near the station."
- Complete the short answer: "Did the train arrive late?" — "Yes, it ___."
- Fill in with the main verb: "My brother ___ his project on Saturday." (past tense of do)
Answers: 1. Does; 2. did; 3. do; 4. does; 5. Did you go to the party? 6. He doesn’t like mathematics. 7. They didn’t watch the film. 8. Does Ananya live near the station? 9. did; 10. did.
Summary
Do goes with I, you, we, they and plural nouns, does with he, she, it and singular nouns, and did is the past form for all subjects. As helping verbs they make negatives (don’t, doesn’t, didn’t) and questions in the simple present and simple past, and the main verb always stays in the base form. As main verbs they mean “perform”, as in do homework. Use them for emphasis in positive sentences (I do like it), and do not use them with be, modal verbs, or questions where who/what is the subject.