Adding accented characters to textivate...

OK, so there is no textivate-specific way to add accented characters or special characters to textivate.

Note that most textivate exercises DO NOT require the student to type in accented characters. The only exception to this is the Gap-fill (and user-defined Gap-fill) activity, and only when no word list is provided. 

But as a teacher creating your own resources, you will want to make sure that all the special characters are included in your resource.