Yema means yolk- you know, the kind that comes from an egg.
My name is particularly difficult for Hispanic people to say. I often get called egg yolk, or flame.
Maybe this would bother me, but I'm quite sure that I do such an awful job of saying some of their names that I almost welcome it so that I don't feel quite so bad about my incompetence. For example how would one pronounce Ximena? See- Men- ah, not X-e-meaner as this ignorant foreigner figured out while doing attendance and getting blank stares from everybody. One point for me.
This embarrassment can be avoided by checking over attendance lists before class and asking trusted colleagues how to pronounce the names. Alternately, ask them to sign in using a book- that won't help you learn their names though!