"They would need to change their clothes."
Translation:Ils auraient besoin de changer de vêtements.
To understand the structure of this sentence you need the following:
In French certain verbs are followed by the preposition de + noun. Changer is such a verb
structure: changer + de + noun without a determiner
Je vais changer de chemise - I am going to change my shirt
changer de chaussure - to change into other shoes
changer de maison - change houses
changer de train - change trains
In English, we can say "change clothes" or "change my clothes." (though there is not really a difference in meaning.) Is the latter not possible in French as a distinct structure?
I don't quite understand why you are saying "changer de vêtements" is an example of changer as an intransitive. Surely vêtements are the things being changed? Seems quite transitive to me. My dictionary shows the construction "changer de" as being transitive only.
you are right, my mistake. I have modified my previous reply.
I was wondering that too! Unfortunately I put leur instead of leurs so I can't tell you if it's accepted.
i suppose it is not an exact translation; yours means 'it would be necessary that they change their clothes'; it means more or less the same thing but isn't exact
and why not: ils auraient besoin de se changer; se changer means to get changed as in change clothes
Yes, this is a fixed idiomatic phrase. You might theoretically change a baby's clothes for them but normally the clothes are implicitly yours.