Concordances and Collocations
Concordances -- kWIC format
The original concordances were book concordances in which an important work such as the bible was rearranged so that all instances of a word (e.g., forgive) are listed together, one instance to a line along with the preceding and following words.
This format (KWIC -- keyword in context) is very useful for getting an idea of the different uses or meanings of a word and for finding common patterns or phrases.
These days it is possible to use concordance software to generate a concordance.
Different uses of a word are often associated with different collocations (i.e., accompanying words). Thus you might find the verb post associated with letter in some lines and with notice in others.