I would suggest very familiar, somewhat familiar, and unfamiliar.
Whatever words or phrases you ultimately suggest, though, I would suggest providing basic definitions within the instructions of the test. (An individual's self-reported familiarity can vary depending on how they interpret the word). So, I'd suggest something along these lines:
For each of the following, indicate how familiar you are with the word, using this scale:
I am very familiar with this word: I understand what the word means, and I'm confident I could the word correctly in conversational English.
I am somewhat familiar with this word: I understand its meaning, but I might be reluctant to use it in conversation, because I'm not completely sure of how to use it properly.
I am unfamiliar with this word: If I were to hear this word in conversation, I might be able to deduce its meaning based on context, but, but itself, I'm not sure what the word means, or how it is properly used.