Hay mucha pimienta, clavos, y canela en el mercado de Londres: There are much pepper, cloves, and cinnamon in the London market.
Sí, hubo muchas especias el año pasado también: Yes, there were many spices last year also.
Cuando estaba en El Cairo había miedo de que estallara algún motín: When
I was in Cairo there was the fear of some riots breaking out.
(N.B.—Impersonal verbs are only used in the 3rd pers. singular.)
In English we have "there is" and "there are," because "there to be" is not used impersonally, the meaning being, e.g., "a man is there"; "two men are there." In Spanish, however, haber is used impersonally and both "there is a man" and "there are two men" are translated "Hay un hombre," "Hay dos hombres."
It will be noticed that Haber used for "there to be" makes Hay instead of Ha for the present indicative. All its other tenses remain unchanged: había, hubo, habrá, habría, etc.
Hay que followed by an Infinitive (French "il faut"), it is necessary to …, as—
Hay que tener mucho cuidado: It is necessary to be very careful. I, you, etc., must be very careful.
Tener is generally a =principal= (viz., not an auxiliary) verb, used to denote possession; but it is used sometimes as an =auxiliary= instead of haber, as—
Tengo recibido su catálogo ilustrado y lista (or boletín) de precios: I have received your illustrated catalogue with price list.