A method of operating a computer to perform linguistic analysis includes the steps of splitting an input text into words and sentences; for each sentence, comparing phrases in the sentence with known phrases stored in a database, as follows: for each word in the sentence, comparing its value and values of words following it with values of words of stored phrases, starting with the longest stored phrase that starts with that word, and working from longest to shortest; in the event a match is found for two or more consecutive words, and considering the words around the phrase, labelling the matched phrase with an overphrase that describes the grammar use of the matched phrase; after the penultimate word has been compared, recasting the sentence by replacing the matched phrases by their respective overphrases; and then repeating the comparison process with the recast sentence until there is no further recasting.