This document discusses how online corpora can be used as a tool by literacy teachers. It begins by defining what a corpus is - a large database of representative language samples used for linguistic research. It then provides examples of free online corpora like COCA that teachers can use to answer questions about language patterns and usage. The document outlines how to effectively search corpora and interpret results, as well as limitations to be aware of. It also provides ideas for how teachers can incorporate corpora into classroom activities and lessons.