I am reading a manga and a girl is showing her tutor that she "started her test." All she has is her name written down. Here is the sentence. お前しか書けてないがいいぞ. I believe the tutor has said this. The preceding sentence was said by the girl and was 私もう始めてます。
I can't quite pick up on what is being said here. It seems like 書けてない is the negative potential form of 書く. So my obviously wrong translation is, "Not being able to only write your name is good." This makes no sense. I'm just taking every word at face value so to speak. If anyone could provide a proper meaning for this sentence, I would greatly appreciate it.