Is "haber" always a helping verb?

Question

In this sentence:

Lamento que no haya más galletas.

there is only a "helping" verb, but none other. I thought there should be another verb, also. Help me understand this, please.

Answer 1

In this case, haber is not a helping verb, but rather an impersonal verb.

You can see this from the fact that haber is not followed by a past participle.

Lamento que no haya más galletas

vs

Lamento que se hayan comido todas las galletas.

There, you have your verb, comer, being helped by haber

When haber is used impersonally, it expresses the existence of something, tangible or not.

Hay que aprender para saber.

Hay dos iguanas en el baño.

Había una fantasma en el closet.

Hubo sol ayer.

¡Habrá comida gratis!

Answer 2

The previous one is not exactly the right answer, I'm afraid.

Lamento que no haya más galletas

(There's no more biscuits left, but I'd like there were :()

haya = verb "haber", presente de subjuntivo. Meaning: to remain, to leave, to be. haber is the main verb here, because it doesn't act as an auxiliary verb, but as an "action" verb, with its own meaning. It's subjunctive because I'd like more biscuits, but actually there are not.

Lamento que se haya comido todas las galletas.

(I'm sad because all of the biscuits have been eaten)

haya = verb "haber", pretérito perfecto compuesto de subjuntivo (haya /-s /-amos /-ais /-an + participio). That is: haya acts as auxiliary verb here. The main verb here is "comido". The action happened in the past, that's why a past tense is used here.

There's no impersonation, the thing is rather different: the first example is simple present, the second one is a composite past tense.