Is there any difference between "come in" and "come on in"?
Native speaker’s answer
Rebecca
There really is no difference between the two apart from nuance. "Come in" has a more formal tone. It sounds more like an instruction or a command, rather than an invitation. When someone or a situation is more relaxed and friendly, we may adopt a more inviting and encouraging tone. "Come on in" conveys that sense of encouragement and invitation better than "come in". Ex: Oh, you're here! Come in. Ex: Oh, you're here! Come on in.