There are two mas. Mas with or without accent. Más is adverb.Mas is also conjuntion. It means even when they are invariable in shape. The shape can´t change. It does not form plural or gender. Both are use with rather a different meaning and location in the phrase. Más... is the quantity adverb. More. I want more sugar: Yo quiero más azúcar. Mas... is the conjunction "pero".Adversative conjunction. ( I think I remember, not quite sure if adversative or other similar type ). I went to Rome but I couldn't visit the Coliseum. Yo fui a Roma más/pero no pude visitar el Coliseum.