What is he replies fast but never initiates?

If someone replies quickly but never initiates a conversation, it could mean that they are not very confident or comfortable with starting a conversation themselves. They may prefer to respond to messages rather than taking the lead in a conversation. This behavior could also indicate that they are busy or simply not interested in keeping up regular communication with that particular person. It's important to communicate openly with them and see if there's something specific that's causing them to hold back from being more proactive in initiating conversations.