Ce dont, la façon dont, dont deux filles

ce dont: what

With no noun in front, dont becomes ce dont, the way que becomes ce que. English says what. The verb in the clause decides which one:

• Je sais ce dont tu parles. - I know what you are talking about.
• Tout ce dont je me souviens, c'est le bruit. - All I remember is the noise.
• Ce dont j'ai besoin, c'est d'un peu de calme. - What I need is a bit of peace.

In the last one, the de of avoir besoin de comes back after c'est: c'est d'un peu de calme. Careful writing keeps it; everyday French often drops it, as in the second example (c'est le bruit).

la façon dont: the way

La façon de faire quelque chose has a de in it, so the way someone does something is la façon dont. The same goes for la manière dont.

• La façon dont il parle me fait rire. - The way he talks makes me laugh.
• J'aime la manière dont elle travaille. - I like the way she works.

English speakers reach for que or dans laquelle here. Neither works: it is la façon dont.

dont with numbers: dont deux filles

After a total, dont introduces part of it: of whom, of which, including. The part often has no verb.

• Il a trois enfants, dont deux filles. - He has three children, two of them girls.
• J'ai lu dix livres, dont trois en français. - I read ten books, three of them in French.
• Vingt personnes, dont le directeur, étaient là. - Twenty people, including the director, were there.
• Elle a deux frères, dont l'un vit au Canada. - She has two brothers, one of whom lives in Canada.

Add a verb and the plain order returns: J'ai trois sœurs, dont deux vivent à Paris. - I have three sisters, two of whom live in Paris. Newspapers use this constantly.

Mistakes English speakers make

The last row is about a real place: la ville d'où il vient, the town he comes from. Dont for a place survives only in older literary French; modern French uses d'où. For family origins, dont is still normal: la famille dont il est issu, the family he comes from.