Learn French: Nous avons reçu vingt maquettes, dont cinq sont écartées. - We received twenty scale models, five of which are discarded.

Nous avons reçu vingt maquettes, dont cinq sont écartées.

We received twenty scale models, five of which are discarded.

Breakdown of Nous avons reçu vingt maquettes, dont cinq sont écartées.

être

to be

nous

we / us (object pronoun)

Questions & Answers about Nous avons reçu vingt maquettes, dont cinq sont écartées.

How exactly does dont work to mean "of which" in this sentence?

In this context, dont indicates a subset. It replaces de ces maquettes (of these models). So dont cinq translates as "five of which" or "five of them". In French, putting dont before a number or quantity is the standard way to extract a subset from a group you just mentioned.

Why is écartées in the feminine plural form (-ées) if its subject is just the number cinq?

The number cinq is acting as a pronoun that stands in for "five models". Because it refers directly back to maquettes, which is a feminine plural noun, the past participle écartées must agree with it.

Could I say cinq desquelles instead of dont cinq to mean "five of which"?

No, that wouldn't be natural here. While desquelles also means "of which", French generally requires dont when extracting a portion using a number (like cinq) or a quantity word (like plusieurs). You simply place dont right before the quantity.

What is the exact nuance of the verb écarter here?