Parts of Speech is a free writing add-on for students who want to practice identifying and labelling the parts of speech; it is also for teachers who want to formatively assess their students' skills identifying, labelling, and using the parts of speech in writing. The add-on allows users to highlight each part of speech with a different background color. Additionally, the Parts of Speech toolbar tracks the occurrences of each part of speech labelled, and the occurrences can be exported into a table at the end of the document. The add-on was designed as a tool to support learning and instruction. Therefore, it requires manual input from the user and does not automatically label the parts of speech in a document or verify the accuracy of a user's input.