I really liked this kata. Some people didn't like the "hardcoding", but maybe some problems genuinely require it and this is a really practical example. Here in Java we've got it down to not much more than a single switch statement (with 30 cases).

Wait! The (?i) does not work with diacritics - this regex will actually not match uppercase vowels such as  or à like it looks like this solution is trying to do.