Google Ngram is an easy but incredibly useful tool. I know I have used it for previous research projects in a variety of classes. You can track the prominence of words or phrases over time in Google books. You can set the span of time to focus on a long period of time or a specific period to track the use of phrases over a short period. You can also choose a few different languages; American English, British English, French, Chinese, etc. A wildcard search can be helpful if you want to look up the top words that follow after another word, you can put a “*” in place of a word, the graph will display the top ten substitutions. Inflection search can be used to represent various grammatical categories of one word; so if you put in “give_INF thanks”, results for “giving”, “gave”, “gives” will be included. You can also make distinctions between different parts of speech for the same word; inputting “bait_NOUN”, “bait_VERB” will produce two different results. Dependencies can be used instead of patterns to see how a word can modify another word. Inputting “beautiful=>woman” will produce all instances of “beautiful” being applied to “woman.” There are a lot of ways to combine these particular things together in specific ways to really confine your search results.
This tool can be used in so many ways for so many different things; it is vital resource for linguistic analysis.