I had someone sharing my home for approximately 1 year. He had full access to my home. I think this is accommodation sharing. What can I deduct on my income tax

I neglected to mention that he paid me an amount every month

From the CRA documentation "Renting Below Fair Market Value":

You can deduct your expenses only if you incur them to earn income. In certain cases, you may ask a relative or someone else living with you, to pay a small amount for the upkeep of your house or to cover the cost of groceries.

You do not report this amount in your income, and you cannot claim rental expenses. This is, in fact, a cost-sharing arrangement, so you cannot claim a rental loss.