Instinctive knowledge of collocations, in both senses, is a characteristic of the fluent user of a language. Thus, a knowledge of collocations is vital for successful mastery of English. The concordance is at the centre of corpus linguistics, because it gives access to many important language patterns in texts. A concordance is a list of all the words, or a certain word, used in a text or a body of texts, together with the context in which the words appear. This context is usually no more than 7 or 8 words to the left and right of the node word.
Concordances are lines of text.
Each line contains a node word or phrase, which is usually in the centre of the page. The words to the left and right of the node are the context in which each instance of the word or phrase appears in a certain text. The node is the word or phrase for which the 'researcher' elected to search. The number of words to the left and right of the key word or phrase can often be adjusted. This means that a concordance line need not always have to be just one line of text with about six or seven words to the left or right of the node.