Why does this girl reply to only specific messages that I send and leave the rest on read?

[winterfox10]

If she isn't returning your flirts, then she's either not comfortable yet, or not not interested. I once read a meme about women: "If it isn't a resounding yes, it's a no."

[Wise4myage]

I agree, you need to ask her. Maybe she doesn't feel comfortable answering certain types of questions or flirting bothers her?

[Tedee18]

Ask her.