After you have prepared on your own by actively reading a variety of texts on your own that interest you, and have applied the skills of writing short answer and supported opinion paragraphs for your teachers to get feedback on your skills, it is time to take a practice test!
The Education Quality and Accountability Office (EQAO) that runs the OSSLT provides a sample test online for you to practice. Trying the sample test will help you familiarize yourself with the test tools and how to navigate. In addition the Peel District School Board has created a series of online practice assessments to help you be ready!