This webpage has an online workbook designed to help you improve your vocabulary. There are six units and 24 lessons on topics such as parts of speech, with a variety of exercises to help you learn new words commonly used in the Canadian workplace. It includes crosswords and wordlists with definitions to help you learn and retain vocabulary, and has an answer key at the end so you can review your answers.
This resource is appropriate for people with a high school reading level and above.
Government of Canada