How do I add languages in speech/rotary options in OS X?

Is there a way to add more languages for VoiceOver in OS X?
Iʻve got just Alex. But as I read and write in more than one language, iOS is easier to use when I need to pick the language the text to be read (or to be written) is in.
Iʻd love to add some of the languages I frequently use, and then use rotary to pick the language. But rotary only gives me 4 lousy options - when I get it to work. Nothing for languages.
Is there something Iʻm missing?
Yosemite, 10.10.2.
Alex / UEB (no braille keyboard or display so UEB is merely cosmetic choice)