As an auxiliary verb to form compound tenses: When used in this way, haber is the equivalent of the English auxiliary verb "to have" (which is much different than the English "to have" when it means "to possess"). Haber is used in a variety of tenses to form what are known as the perfect tenses because they refer to actions that have been or will be completed. As in English, the perfect tenses are formed by following a form of haber (it is conjugated irregularly) with a past participle.
- Examples: He comprado un coche. (I have bought a car.) ¿Has estudiado? (Have you studied?) Han salido. (They have left.) Habrá salido. (She will have left.) Habría hablado. (I would have spoken.)
As a beginner, you don't need to learn all the tenses using haber now, but you should be able to recognize haber when it is used. You should also be aware that while the perfect tenses in Spanish and English are quite similar in form and usage, they aren't always used in exactly the same way.
To mean "there is" or "there are": One peculiarity of haber is that it has a unique conjugated form, hay (pronounced basically the same as the English "eye") that means "there is" or "there are."
- Examples: Hay una silla en la cocina. (There is one chair in the kitchen.) Hay dos sillas en la cocina. (There are two chairs in the kitchen.)
Haber can be used in this way in tenses other than the present, although not as commonly.
In various idioms: Haber can be used in a number of idioms, which are phrases that have a meaning apart from the meanings of the words in them. The one you'll run into most often as a beginner is haber que, which means "to be necessary" when followed by an infinitive. When used this way in the present tense, the hay form of haber is used.
- Examples: Hay que saltar. (It is necessary to jump.) Hay que conocerlo para comprenderlo. (It is necessary to know him in order to understand him.) Habrá que salir a las dos. (It will be necessary to leave at 2 o'clock.)