1. A method in a computing device for searching for sentences, the method comprising: providing a collection of sentences; for each sentence in the collection, identifying by the computing device pairs of collocated words of the sentence; for each identified pair of collocated words, identifying by the computing device a part of speech of each word of the pair; generating a first part of speech and word pair that includes the identified part of speech of the first word and the second word and a second part of speech and word pair that includes the first word and the identified part of speech of the second word; and generating a mapping from the first part of speech and word pair and the second part of speech and word pair for the sentence; receiving an input query that includes a first word, a part of speech, and a second word; identifying from the mapping sentences that include the first word of the input query collocated with a word with the part of speech of the input query and a word with the part of speech collocated with the second word of the input query; and displaying to a user the identified sentences.