Learn French: On organise une soirée ce week-end. - We are organizing a party this weekend.

Even though on is used to mean "we" in everyday French, it is grammatically a singular pronoun (like "he" or "she"). Because of this, it always takes the same verb conjugation as il or elle. So, we say on organise.

Doesn't une soirée mean "an evening"? Why does the translation say "a party"?

You are right! Une soirée refers to the time spent during the evening. However, it is also the most common everyday word for an evening party or get-together.

Why is there no word for "are" in on organise?

In French, the present tense covers both the simple present and the continuous present. On organise translates to both "we organize" and "we are organizing". You don't need a separate word to say "are".

Why do we use ce before week-end?

The word ce is a demonstrative adjective meaning "this" or "that" for masculine singular nouns. Since the borrowed word week-end is masculine in French, "this weekend" translates to ce week-end.