Following are the most common idioms using haber. For other usages of haber, see lessons on its use as an auxiliary verb and as a translation for "there is" or there are." Also note that the conjugation of haber is highly irregular.
- haber (in the third-person singular) que + infinitive — to be necessary to, to be essential to — Hay que comer. It is necessary to eat. Habrá que salir a las tres. It will be necessary to leave at 3.
- haber de + infinitive — to be to, to be supposed to — Hemos de salir as las tres. We are to leave at 3. He de viajar a Nueva York. I am supposed to go to New York.
- haber de + infinitive — must (in the sense of showing high probability) — Ha de ser inteligente. He must be intelligent. Había de ser las nueve de la noche. It must have been 9 p.m.
- había una vez (or, less frequently, hubo una vez) — Once upon a time ... — Había una vez un granjero que tenía una granja muy grande. Once upon a time there was a farmer with a very large farm.
- no haber tal — to be no such thing — No hay tal cosa como un almuerzo gratis. There's no such thing as a free lunch.
- ¡Qué hubo!, ¡Quihúbole! (regional variation) — Hi! What's happening?
- No hay de qué. — Don't mention it. It's not important. No big deal.
- habérselas con — to have it out with, to quarrel with — Me las había con mi madre. I had it out with my mother.
- ¿Cuánto hay de ... ? — How far is it from ... ? — ¿Cuánto hay de aquí a Londres? How far is it from here to London?
- ¿Qué hay? ¿Qué hay de nuevo? — What's happening? What's new?
- he aquí — here is, here are. — He aquí una lista de nombres. Here is a list of names.
- Heme aquí — Here I am.
- He lo aquí. He lo allí. He los aquí. He los allí. — Here it is. There it is. Here they are. There they are.
- ¡He dicho! — And that's that!

