Can relatives speak?

Since I came to D & D, I have wanted to make a non-verbal character. I know, I know, that's pretty weird, but I like a challenge, and I thought it was really fun.

But I was thinking that it would be quite difficult to communicate with the rest of the members of my group. If the DM does not allow a type of sign language, I wanted to create a form of communication in the world. I'm looking for something like "talk telepathically with the familiar and have me repeat what I've thought out loud."