TT Checkup, All Streets OK?

[Moozh]

I had a hard time putting this guy on a hand, so I was hoping to get a few responses to see if I had the right idea...

I don't have the HH available so this is from memory...

.50/1 blinds. I raise to 4 with TT and get one caller behind me.

The flop is 992 (no flush), the pot is 9.5. I bet 7, he calls. What could he have?

The turn is a Queen, giving 992Q, the pot is 23.5. I bet 17, he calls. Still very confused...

The river is a blank, the pot is 57.5. I check, he bets 25. What could he have and what do I do?