A common doubt for spanish speakers, confusion between "but, although" and "more, plus" because of the diacritic accent. Used in US as well
"Eran cinco, tal vez de veinte años o más. No me dio miedo, mas huí de ellos. -> There were five, maybe in their twenties or more. I was not scared, but I flee from them."
* Only one "like" per meaning and day, the more "likes" the meaning will appear higher in the list