English, of course, is a no-brainer for regex because that\'s what it was originally developed in/for:
Can regular expressions understand this charact
Short answer: yes.
More specifically it depends on your regex engine supporting unicode matches (as described here).
Such matches can complicate your regular expressions enormously, so I can recommend reading this unicode regex tutorial (also note that unicode implementations themselves can be quite a mess so you might also benefit from reading Joel Spolsky's article about the inner workings of character sets).