I thought the creators might have actually made a language that you could translate but it doesn't look like it.
The problem I ran across was that the language doesn't consist of just words. It consists of pictures that appear in the conversation/thought bubbles above the sim's heads. Likewise, certain phrases are only spoken by a particular age bracket or gender. It's a language that transmits basic concepts, so a word for word translation isn't possible. But there are certain phrases that are only spoken in certain circumstances, and as a result of that, a basic conceptual translation of phrases is quite possible.
Here's a couple that I know for sure:
Female: "Za woka jenava!" - I think you're hot! (flirting)
Female: "Sulsul! Plerg Majah Bliff? - Hello! Can I go and do something else? (a need is low)