Trabajar is an infinitive verb because it ends in ar. Verbs in infinitive are the most basic form of a Spanish verb. So this type of verbs aren't conjugated and don't tell us anything about the person who performs an action or the tense of the sentence. So infinitive verbs have an <em>ar, er </em>or <em>ir </em>ending.
bro creo que se te olvido poner la pregunto osea por ejemplo compre 10 caja de regalo con 50 juguetes o algo asi se te olvido poner si lo pones quizas te pueda ayudar en tu probblema