I believe it's because "travail" is the noun and "travaille" is a verb, the conjugated form of "travailler"
Why not à enterprise instead of dans enterprise?
I put à cette entreprise and it was marked wrong because Duo says it should be dans but I don't understand the reason behind it...help !
Why travaille and not travail ?
It has to be il a travaillé, right?
I get confused with when to use travail, travaille and travailler too?
I just had the phrase order reversed , so unless there's some quirky reason why that's not OK , my answer was identical in meaning and I used exactly the same words .