After going through all of these answers I found a way to build a tiny regex that supports most languages and only allows for word characters. It even supports some special characters like hyphens, spaces and apostrophes. I've tested in python and it supports the characters below:
^[\w'\-,.][^0-9_!¡?÷?¿/\\+=@#$%ˆ&*(){}|~<>;:[\]]{2,}$
Characters supported:
abcdefghijklmnopqrstwxyz
ABCDEFGHIJKLMNOPQRSTUVWXYZ
áéíóúäëïöüÄ'
???
lLoOuUZàáâäãåacceèéêëeiìíîïlnòóôöõøùúûüuu
ÿýzzñçcšžÀÁÂÄÃÅACCEEÈÉÊËÌÍÎÏIL
NÒÓÔÖÕØÙÚÛÜUUŸÝZZÑßÇŒÆCŠŽ.-
ñÑâê?????????????
????????? ?????? ??