12. A server, comprising: a memory configured to store a phrase table for statistical machine translation, the phrase table including a plurality of phrase pairs corresponding to one or more pairs of languages; and one or more processors configured to: determine a redundant set of the plurality of phrase pairs, the redundant set of the plurality of phrase pairs including each of the plurality of phrase pairs having a phrase matching a phrase of another of the plurality of phrase pairs, wherein each phrase of the plurality of phrase pairs includes two or more sub-phrases, calculate a first probability for each specific phrase pair of the redundant set of the plurality of phrase pairs, the first probability indicating a likelihood that its corresponding specific phrase pair is an appropriate translation, calculate a second probability for each specific phrase pair based on third probabilities of the sub-phrases of the specific phrase pair, the second and third probabilities each indicating a likelihood that a corresponding specific phrase pair or sub-phrase is an appropriate translation, compare the first and second probabilities for each specific phrase pair to a probability threshold indicative of an acceptable change in probability distribution of the phrase table, select each specific phrase pair when its corresponding second probability is within the probability threshold from its corresponding first probability to obtain one or more selected phrase pairs, and remove the one or more selected phrase pairs from the phrase table to obtain a modified phrase table.
13. The server of claim 12 , wherein the one or more processors are further configured to divide the redundant set of the plurality of phrase pairs into two of more subsets based on a number of sub-phrases in each phrase pair of the redundant set of the plurality of phrase pairs, wherein each subset corresponds to a specific number of sub-phrases.