Learn Italian: Facciamo l'inventario per vedere quanti ce ne sono. - We do the inventory to see how many of them there are.

ci sono simply means there are. However, because we are asking about a quantity of something previously mentioned, meaning how many of them, we must include the partitive pronoun ne (of them). When the existential ci (there) combines with ne, its vowel changes to an e, resulting in ce ne sono.

How do we know to use quanti instead of quanto?

The word for how much or how many must agree in gender and number with the items being counted. Because we see the masculine plural quanti, we know the unstated items are masculine, such as i prodotti (the products). If we were counting feminine items, the sentence would end with quante ce ne sono.

Why is vedere preceded by per?

In English, we often just use the infinitive to express the purpose of an action, like saying we do the inventory to see. In Italian, to express this in order to meaning, you must use per followed by an infinitive verb.

Why does Italian use facciamo for taking an inventory?