Both do and does are present tense forms of the verb do. Which is the correct form to use depends on the subject of your sentence.
In this article, we’ll explain the difference between do and does, cover when and how to use each form, and provide examples of how they’re used in sentences.
⚡ Quick summary
Do is an irregular verb, which means that it has different forms depending on tense and the subject it’s being used with. Both do and does are used for the present tense. The form does is only used with third person singular subjects, such as the pronouns he, she, and it, as in She does yoga. The form do is used for all other subjects, including for first person (I and we) and second person pronouns (you) and the third person pronoun they (regardless of whether it’s singular or plural), as in I do yoga, but they do not. The past tense form of do is did, and the past participle form is done.
do vs. does
The verb do is considered an irregular verb because its past tense and past participle are not formed by adding -ed or -d to the end of the base form as is the case in most verbs. In fact, do has a particularly unusual conjugation pattern compared to other verbs.
Here are the different forms of do:
- do: Base/infinitive; used for present tense except with third person singular subjects (other than the singular they, which uses do regardless of whether it’s singular or plural).
Example: I do my homework as soon as I get home.
- does: Used for third person singular present tense (other than singular they).
Example: She does her homework as soon as she gets home.
- did: past tense
Example: She did her homework as soon as she got home.
- done: past participle
Example: She had done homework for three hours after she got home.
- doing: present participle and gerund
Example: She is doing her homework.
The forms do, does, and did are also used in the negative contractions don’t (do not), doesn’t (does not), and didn’t (did not).
For example:
- Don’t open the window.
- Luke doesn’t know how to cook.
- Fortunately, the flowers didn’t wither.
Verbs similar to do
The irregular verb do has a unique conjugation pattern. Some other irregular verbs that have an unusual conjugation pattern somewhat similar to do are go, be, and have.
| Base/Infinitive | Present Tense | Past Tense | Past Participle | Present Participle |
| do | do/does | did | done | doing |
| go | go/goes | went | gone | going |
| be | is/are | was/were | been | being |
| have | has/have | had | had | having |
To learn more about the forms of the verb be, check our guides to is vs. are, been vs. being, and has been vs. have been.
Examples of do, does, did, and done used in a sentence
The only thing left to do is look at how we typically use the forms do, did, and does in sentences.
- I’ve never done yoga, and I’m not sure if they do, but I’m sure that he does.
- I remember what I did last time, but I’m not sure if I should do it again.
- She did everything she could to make sure it was done by the deadline.
- I can’t do even a fraction of the amazing things that my brother does on a regular basis.
- We did the vacuuming yesterday, the morning crew does the laundry on Fridays, and the night crew will do the floor waxing next month.
