Learn French: Vous êtes des gens sympas.

Adjectives in French must match the noun they describe. Since gens (people) is plural, we add an -s to the adjective sympa to make it plural too. Remember that this -s is silent!

Why does it say gens sympas instead of sympas gens?

In French, most adjectives come after the noun they describe. So instead of saying 'nice people', the sentence literally says 'people nice'.

The English translation is 'You are nice people.' Why is des needed in French?

In English, we often drop the word 'some' and just say 'nice people.' In French, you almost always need an article before a noun. des is the plural indefinite article (the plural of un or une), so it acts like an invisible 'some' here.

Is sympa a masculine or feminine adjective?

It works for both! sympa is short for sympathique. Because the full word naturally ends in an -e, it is used for both masculine and feminine nouns. You just add an -s to make it plural, like in this sentence.