8. A non-transitory computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which, when executed by one or more processors, cause the processors to perform operations comprising: receiving a first message from a client device; determining that the first message includes a first portion in a first language and a second portion in a second language, the second language being different than the first language; translating the first message into a second message in the second language; and returning the second message to the client device, wherein the first message is a speech message, the second message is a speech message, the translating further including: generating, based on the first message, a third message using a bilingual speech recognition system for the first language and the second language, the third message being a textual message including a first portion in the first language and a second portion in the second language, the third message being a speech-to-text transform of the first message; translating the third message into a fourth message using machine translation, the fourth message being a textual message in the second language; and generating, based on the fourth message, the second message using speech synthesis, the second message being a text-to-speech transform of the fourth message.
10. The non-transitory computer readable storage medium of claim 8 , wherein the first message is a speech message, the determining includes determining the first portion based on an acoustic model associated with the first language and determining the second portion based on an acoustic model associated with the second language.