Do, Does, Did

The words do, does and did often cause confusion in the English language. They are all forms of the verb to do. The verb to do can be used as an action verb and also as an auxiliary verb.

In some cases, to do is used as a verb that expresses an action (just like the verb to walk).

Subject/Verb Agreement Using to do as an Action Verb

Subject	Forms of to do in each Tense				Rest of Sentence
	Present	Past	Perfect Form	Continuous Form
I / You / We / They	do	did	have/had + done	am/are/were + doing	a good job
He / She / It	does	did	has/had + done	is/was + doing	homework

Examples

1. Pete always does his taxes on time.
2. Volunteers do a lot of work around the town.
3. Gil did a great job on his history report for school.
4. You have done nothing all morning!
5. I am doing the best I can!

It is also common to use do, does and did as auxiliary verbs (or helping verbs) together with another verb in its base form. This is used to create negative sentences, questions, or for adding emphasis.

Negative sentences with do not, does not and did not

When creating negative sentences, we usually use shortened forms: don't, doesn't and didn't together with the base form of the verb. Note: Save the long forms (do not, does not and did not) for when you want to create emphasis. When speaking, you would put an accent on the 'not'.

Subject	Auxillery Verb to do Present or Past		Verb in Base Form	Rest of Sentence
I / You / We / They	don't (do not)	didn't (did not)	sleep	late
He / She / It	doesn't (does not)	didn't (did not)	sit	out in the sun

Examples

1. Your client doesn't understand the contract.
2. You don't need to worry about me.
3. Your friends didn't get the e-mail.

To create a question that will be answered with a yes or no, start the question with Do, Does or Did, (Doesn’t, Don’t, Didn’t) for a negative question) then add a subject (the person or thing that does the action) followed by the base form of the verb and only then add the rest of the sentence.

Auxiliary Verb 'To Do'		subject	verb in base form	rest of sentence
Present	Past
Do	Did	I / you / we / they	drink	enough water
Does	Did	he / she / it	eat	meat
Don't	Didn't	I / you / we / they	write	to them

Examples:

1. Do you want to go to the party?
2. Does your dog live outside or in the house?
3. Does your sister always talk so much on the phone?
4. Did you catch the bus this morning?
5. Don't you ever visit your parents?
6. Didn't Mr. Albertson call you?

Note: Time Expressions:

1. You may add a one-word time expression, such as always, usually, or often between the subject and the verb.
2. You may use a negative question with a time expression such as 'ever'.

Wh- questions are questions that require more information in their answers. Typical wh- words are what, where, when, why, who, how, how many, how much. To create a wh-question, start with the wh-word, then add do, does or did, then the subject (a person or thing that does the action), followed by the base form of the verb and only then add the rest of the sentence.

Wh-Word	Auxiliary Verb 'To Do'		Subject	Verb in Base Form	Rest of Sentence
	Present	Past
Where	Do	Did	I / you / we / they	get	the maps
Why	Does	Did	he / she / it	sit	out in the sun

Examples

1. Where do you want to send the package?
2. Why does she always scream like that?
3. How much do these earrings cost?
4. Why don't you ever clean up your mess?
5. When did they arrive home?

Fill in the correct form of the verbs as in the examples:

1. Mark and Dylan do volunteer work at the homeless shelter twice a week. (do)
2. Sheila didn't do the dishes last night. (not do)
3. Does Gillian usually meet clients so late at night? (meet)

1. ________ John often _____ together with his friends on the weekends? (get)
2. Sivan ____________the post every day. (not collect)
3. _______ the computer ____________ again yesterday? (break down)
4. ____________ work __________ he _______ every month? (how much/do/do)
5. _________ you ________ your laundry now? (do)
6. In general, the dogs ____________ on the beds in his house. (not sleep) They _____ last night though. (do)
7. How many copies of the document_______ you _________? (need)
8. I ________ ever___________ the street on a red light! (not cross)
9. ________ Adam always _________ the lights off when he leaves the office? (turn)
10. _________ she ________ her homework yet? (do) It's due tomorrow.

Answers:

1. Does/get
2. doesn't collect
3. Did/break down
4. How much/does/do
5. Are/doing
6. don't sleep/did
7. do/need
8. don't/cross
9. Does/turn
10. Hasn't/done

Positive

1. Pete always does his taxes on time.
2. Volunteers do a lot of work around the town.
3. Gil did a great job on his History report for school.
4. You have done nothing all morning!
5. I am doing the best I can!

Negatives

1. Your client doesn't understand the contract.
2. You don't need to worry about me.
3. Your friends didn't get the e-mail.
4. I do not want to go with you!

Yes/No Questions

1. Do you want to go to the party?
2. Does your dog live outside or in the house?
3. Does your sister always talk so much on the phone?
4. Did you catch the bus this morning?
5. Don't you ever visit your parents?
6. Didn't Mr. Albertson call you?

Wh-Questions

1. Where do you want to send the package?
2. Why does she always scream like that?
3. How much do these earrings cost?
4. Why don't you ever clean up your mess?
5. When did they arrive home?