Learn Spanish (Latin America): Necesitas asignar el transporte antes de que el evento empiece. - You need to assign the transportation before the event starts.

The phrase antes de que (before) always requires the subjunctive mood. This is because it introduces an event that hasn't happened yet relative to the main action. So, we use empiece instead of the normal present tense empieza.

I know empezar has a stem change, but why is it spelled with a 'c' in empiece?

To form the present subjunctive, you usually start with the 'yo' form of the present tense (empiezo), drop the 'o', and add the opposite ending. However, for verbs ending in -zar, the z changes to c before an e to keep the same sound. That spelling rule gives us empiece.

Could I just say antes del evento empiece instead of using antes de que?

No, you need the que. If you are just putting a noun or an infinitive after 'before', you use antes de (for example, antes del evento means 'before the event'). But because you are introducing a whole new clause with its own conjugated verb (el evento empiece), you have to use antes de que.

Why is asignar in the infinitive, but empiece is conjugated?