14. The system of claim 13 , wherein: the second ambiguous word being classified as a non-pinyin word when the probability fails to meet the threshold probability; and a valid non-pinyin word comprises Roman characters that constitute a valid word in the English language.
13. The system of claim 12 , wherein the pinyin classifier is further configured to classify the one or more words adjacent to the first ambiguous word as belonging to the non-pinyin context when the one or more words adjacent to the first ambiguous word are valid non-pinyin words and not valid pinyin words.