Learn Spanish (Spain): Faltan demasiados productos en nuestro inventario. - Too many products are missing from our inventory.

In this sentence, demasiado is acting as a determiner describing the noun productos. Because productos is a masculine plural noun, the quantifier must match it in gender and number, becoming demasiados. If it were modifying a verb or an adjective instead, it would act as an adverb and stay as the invariable demasiado.

Why does the sentence start with Faltan instead of putting the subject first?

Verbs like faltar (to be missing or lacking) often follow the same sentence structure as the verb gustar. The things that are missing (demasiados productos) are actually the subject of the sentence. While you could say Demasiados productos faltan, it is much more natural in Spanish to put the subject after the verb in these cases.

Why is the verb faltar in the plural form (faltan)?

Because the subject of the sentence is the plural phrase demasiados productos (too many products). Since the products are the things that are doing the 'missing', the verb must match them in the plural form.

Why do we use the preposition en when the English translation says 'from'?

The Spanish verb faltar means 'to be absent' or 'to be missing'. In Spanish, you are literally saying that the products are absent 'in' the inventory (en nuestro inventario). English prefers to say missing 'from', but Spanish focuses on the location where the items are not present.