The auxiliary verb DO is required for forming questions with do with all verbs except BE and modal verbs. Here are some examples with Yes / No questions. Remember, it is impossible to ask these questions without the auxiliary verb DO.
| Correct | Incorrect | ||||
| DO | subject | main verb |
|||
| Do | they | eat | meat? | They eat meat? | |
| Does | she | drink | wine? | She drinks wine? | |
| Did | you | dream | last night | You dream last night? | |
| Did | Tom | return | yesterday? | Tom returned yesterday? | |
The same rule applies to Wh– questions.
| Correct | Incorrect | |||||
| Wh– word |
DO | subject | main verb |
|||
| Where | do | they | live | now? | Where they live now? | |
| When | does | the train | arrive? | When the train arrives? | ||
| Why | did | you | call | me? | Why you call me? | |
| How | did | Tom | know? | How Tom know? | ||
Note: It is possible to form questions with the verb HAVE without using DO, but this form is increasingly rare. American English speakers prefer using DO.
| Common | Uncommon | ||||
| DO | sub. | main verb |
|||
| Do | you | have | a pen? | Have you a pen? | |
| Does | he | have | a new idea? | Has he a new idea? | |
Here are examples of correct questions on the left and incorrect questions asked by students who do not know the grammar rules.
| Correct | Incorrect | Reason for error | ||
| Do you speak English? | Are you speak English? | use of BE instead of DO | ||
| Does this train go to Chicago? | Is this train go to Chicago? | |||
| Do you have change for a euro? | Have you change for a euro? | use of HAVE instead of DO | ||
| Does the room have a bathroom? | Has the room a bathroom? | |||
| What time does the bank open? | When the bank opens? | absence of DO when main verb is not BE | ||
| Where do you live? | Where you live? | |||