"Aux" is a contraction of "à les," meaning "to them," and is used when "à" (to) is followed by the plural definite article "les" (the).
Here's how you express "for" in French:
* For someone/something: Use the preposition "pour":
* *Je fais ça pour toi.* (I do this for you.)
* *J'ai acheté un cadeau pour ma mère.* (I bought a gift for my mother.)
* For a specific purpose: Use the preposition "pour":
* *J'utilise ce logiciel pour travailler.* (I use this software for work.)
* *Je suis allé au magasin pour acheter du pain.* (I went to the store to buy bread.)
* For a duration of time: Use the preposition "pendant":
* *J'ai travaillé pendant deux heures.* (I worked for two hours.)
* *Il a plu pendant toute la journée.* (It rained for the whole day.)
Remember: "Aux" is used in specific situations, and "for" is usually translated differently in French.