Have

Have is the second most frequently used verb after be and is the 9th commonest word in the Oxford English Corpus. Together with be and do, it is one of the three primary verbs. As befits such an important word, it has several different uses.

As a full verb it is possibly most often thought of as having the idea of possession (Jane has two cats and a dog.) or doing things (I usually have lunch at home.) It is also used causatively (I need to have my hair cut.).

As an auxiliary verb, it is used in the construction of the perfect aspect (Have you finished yet?).

Auxiliary verb
See main article Present Perfect: Form.
 * Have/has or had is the auxiliary verb used to accompany the past participle, or what Michael Lewis calls the third form, to form the present perfect, the past perfect, the present perfect progressive and the past perfect progressive.
 * As an auxiliary verb, have does not have a progressive form.

Possession
The first meaning that springs to mind for most students is that of have to express possession or relationship, and similar ideas. While this is clearly the case for have got, as we can see in this article, it is not true in the case of have on its own.

States
Although we usually use be to describe physical and mental states or conditions (be happy, be tall, etc.), we can also use have + noun, especially when referring to illnesses and other ailments: She has blues eyes. - I have a headache. - I've got flu.

Actions
We often use have as an "active" verb for everyday actions and experiences. Note that American English often uses take for this (Have a coffee/shower. vs Take a coffee/shower.).

There are two important aspects that distinguish this "active" use of have from the other uses: 1. We use do for negatives and questions (Did you have a good flight?). 2. We don't use got nor contractions/weak forms.

Typical examples

 * have breakfast/lunch/dinner/something to eat/a drink/a coffee, etc.
 * have a bath/a shower/a shave
 * have a chat/a conversation/an argument
 * have fun/a good time/a good weekend - Have fun! - Have a good weekend!
 * have a good journey/trip/flight - Have a good trip!
 * have a walk/a game of (tennis, chess, etc.)/a swim
 * have a look/a try - Let me have a look.
 * have an accident/an operation
 * have a baby/kittens
 * have a call/message (=receive)


 * Note: Although expressions like have a meeting/an appointment/have time may seem similar to this "active" use of have, they are, in fact, considered "possessive" and we can use got with them.

Have (got) to
See main article Have to.

Note also the non-standard form of have got to: gotta, as in A man's gotta do what a man's gotta do!

Causative
When another person, often a professional, does something for us, for instance, to cut our hair or to service the car, that is, does something we cannot easily do (or do not want to do) for ourselves, we often use the structure have + something + past participle (I had my hair cut. - I had the car serviced.). This causative use means that, although we didn't actually do it ourselves, we "caused" a result, albeit by getting someone else to do it for us, and normally to our benefit.

Non-causative
There is, however, a similar structure, often using the past perfect, in which something is done by another person but which affects us negatively: He had his car stolen last week. This non-causative use is very similar to the passive (be + past participle), i.e. His car was stolen last week.

In both cases, have can be substituted by get: I need to have the car serviced = I need to get the car serviced.

Have something/someone + infinitive/-ing form
Slightly more complicated structures than the above are have + object + infinitive (without to) and have + object + -ing. Usage is more informal, and refers to experiences.

As in the above cases, have/had can be substituted here by get/got: I need to have the car serviced = I need to get the car serviced.

Forms

 * have/haven't, has/hasn't, had/hadn't, having

Weak forms
See main article Weak form.

Especially when used as an "action" verb (see above), or in answer to polar questions, have is pronounced /hæv/, has is pronounced /hæz/, and had /hæd/. However, in other cases, unless used as a contraction, we frequently use the weak forms /həv/, /həz/ and /həd/.

Had better
We often use the structure had better ('d better), as in You'd better send it before it's too late, to give strong advice, often with the hint of a threat (...or else!) and with the need for immediate action. It is thus more urgent and more "aggressive" than the more polite should or ought to. In other words, "better" in this case is not a comparative in the sense that you actually have an alternative...

We can make it negative: You'd better not say that to them! Another typical form is the negative interrogative: Hadn't we better let them know before they find out for themselves?

Anticipated difficulties depending on L1
Preconceived ideas and other interferences from L1 obviously interfere in many cases with learning. The following section aims to point out some of the most typical difficulties teachers and students may encounter regarding this particular aspect of language. Students will often clutch at any have they come across and automatically give it its possessive meaning, as a sort of default meaning, and by the time they have recovered sufficiently to remember that it is statistically quite likely to be a mere auxiliary, or an "action" verb, they may have lost the thread of what they have heard or read.

Even if it might not be strictly grammatically precise, it might be useful to point out to students - as a working rule - that although have and have got both have exactly the same meaning in the context of possession, have got somehow implies a sort of addition of something or even a temporary state of affairs, while have is a sort of permanent, neutral state: I have two brothers and a sister - We have a library near us. vs I've got a new car. - I've got a headache.