The Wolfram Language has a wealth of built-in examples that are handy for experimenting and testing. This gives a list of the kinds of examples that are available:

Give the name of a category to see the examples of that type:

Give the specific name to get an example:

This splits the Gettysburg Address text into words:

Make all of the words lowercase so that, for example, “The” and “the” both appear as “the” in the list:

Commonest gives the most common element in a list. “That” is the most common word in the Gettysburg Address:

A “stopword” is a commonly used word like “that” or “the” that doesn’t reveal much about the content of a text.

Use DeleteStopwords to remove insignificant words from a text:

Find the most common significant word: