[tempay]

Have you tried it with other languages, in particular where the user makes a request in one language but expects the call to be made in another?

[addandsubtract]

This. Even if you kinda know a language, speaking to someone on the phone is a whole different ball game. I wish there was an auto-translating STT->TTS tool, or just a TTS tool that auto translates requests into a foreign natural language.