familiar with (someone or something)
Acquainted with or knowledgeable about someone or something. Yeah, I'm familiar with Bill, he seems like a good guy. I'm not familiar with that song—how's it go?
*familiar with someone or something
to have a good knowledge of someone or something. (*Typically: be ~; become ~; get ~.) Are you familiar with changing a flat tire? I can't speak German fluently, but I'm somewhat familiar with the language.