be • do • have
Nouns, Subjects, and Objects
Passive Voice
do
do is used in three different ways in English, and is conjugated, or changed, into do or does in the present tense, did in the past tense, and done in past participle.
1) The meaning of do is to perform an action -
“I do my homework after school.”
“I do the dishes after dinner.”
“I did a lot of things around the house last weekend.”
Note that do is a generic verb, it isn’t very specific. It can usually be substituted for a more specific verb, for example -
“I complete my homework after school.”
“I wash the dishes after dinner.”
“I did a lot of things around the house last weekend.” (In this case, do is the best option, because it can describe different actions around the house, do the dishes, laundry, cleaning, etc.)
2) do is also used with a lot of expressions in English. Here are three common examples -
do good - to do a good job - This expression is grammatically correct, but very common in American English.
“He did really good on his test.”
It is correct when it describes doing something virtuous, of high morals.
“The charity does a lot of good for a lot of people.”
do your best - try to do something as well as you can -
"The first time you do something, you do your best and learn from your mistakes (errors).”
do business (with someone) - to work with someone
"She does business with some of my family members, she’s very professional.”
3) We use do as an auxiliary verb. That means it’s used before another verb, a main verb, to formulate negative sentences and questions in the Present and Past Simple. In these cases, the verb do has no meaning. Its job is to negate (-) a verb in a negative sentence, and structure a question. It is not used as an auxiliary verb with be. This is the only exception.
"I don't (auxiliary verb) know (main verb) the answer.” (Present Simple)
"He doesn't have a car.” (Present Simple)
"I didn't go yesterday.” (Past Simple)
"Do you know the answer?” (In a question with an auxiliary verb, the subject “you” is between the auxiliary verb “do” and the main verb “know”)
"Does she have a car?”
"Did you go yesterday?”
"I’m not sure.” (no auxiliary verb)
"She isn’t my sister.”
"I wasn’t there yesterday.”
"Are you sure?” (no auxiliary verb)
"Is he your brother?”
"Were you there yesterday?”