Saving energy at home

Ils changent de fournisseur has nothing in front of fournisseur, and the gap is not an economy of style: it is the grammar of the phrase. French uses changer in two ways that mean different things. With a plain object, changer quelque chose is to alter the thing itself, so changer sa voiture can only be understood as doing something to that car. With de and no article whatsoever, changer de quelque chose is to give one thing up and take another of the same kind: changer de voiture, changer de train, changer d’avis, changer de sujet, changer de place. The noun stays bare, and more surprisingly it stays singular even when a crowd is involved — les locataires ont changé de fournisseur, one supplier each. An article smuggled back in does real damage: changer le fournisseur says somebody replaced the supplier for everyone. English hides the distinction completely, because « they changed supplier » and « they changed the supplier » differ by a word most speakers would call optional. In French that word is the meaning.