How to extend visit for common-law?

[JuniWolf]

Hello! I am an American who started dating a Canadian last August (in Ontario). I have been visiting Canada off and on since then, and would like to spend more time here. I have read that I should apply to extend my visitor status with the goal of living together for one year to be eligible for common-law.

However, when I fill out the survey to see if I am eligible on the CIC website it says that I am not. Is this because I'm indicating that I am single and have no family here? I don't see an option for my relationship status that matches. I have read that extending visitor status with the goal of common-law eligibility is commonly used and accepted, so I'm just trying to figure out what I'm doing wrong on the website. Any help would be appreciated, as it won't let me start the application until the survey says I am eligible.

I was inspected when I drove here this last time, and the officer suggested a "visitor card" that attaches to my passport so that they don't question me so much when I stay for a long time (because I work from home I can stay for longer than usual). But now that I am looking for something like this I can't figure out what he was referring to, either.