Why would a guy keep adding to a conversation but rarely ask questions?

I (22F) am talking on Instagram dm with a friend (22M) from middle school who seems engaged in the conversation. He responds warmly and often adds new thoughts or topics that keep the conversation going.

For example, if I mention something I’m planning to do, he’ll say it sounds cool and sometimes suggest something related.

But he almost never asks questions back. The conversation still flows, but most of the questions tend to come from me.

I’m wondering what this communication style usually means. Is he just a passive conversationalist, shy, or could it indicate low interest? If he’s not actually interested in talking to me and is just keeping the conversation going to be polite, I don’t want to keep pushing the conversation and make him uncomfortable.

For context, we used to like each other back in middle school but never got together because we were both shy. Two years ago, we went on a date once and had a good time, but since we lived far away from each other, it ended up being just that one date and we didn’t really stay in touch afterward.

Recently, he visited the country where I’m currently studying abroad, and we started talking again. He has already left the country, but we are still chatting on Instagram DMs.

I’d especially like to hear perspectives from people who realize they communicate this way themselves.