Methods and devices for acquiring weighted language model probability and constructing weighted language model

The invention provides a method and a device for acquiring weighted language model probability for a sentence, a method and a device for constructing a weighted language model and mechanical translation method and system based on a corpus. The method for acquiring the weighted language model probability for the sentence comprises the following steps of: weighting the probability of each word group related to the calculation of language model probability in the sentence by utilizing the weight of the word group; and acquiring the weighted language model probability for the sentence according to the weighted probability of each word group related to the calculation of the language model probability, wherein the weight of each word group is set according to the structure of the sentence and used for reflecting the influence degree of the word group on the fluency of the sentence. In the invention, according to the structure of the sentence, each word group related to the calculation of the language model probability in the sentence is assigned with the weight for reflecting the influence degree of the word group on the fluency of the sentence, and the fluency of the sentence can be reflected more accurately on the basis of the structure of the sentence.