Help on a guys text, particularly a guys help.?

Mmk so we text all day every day but lately it's been one worded texts messages or if I'm talking he'll reply with "ya" or "oh" and its confusing but if he text me & I dnt text him back for a while he'll send his text then send another one saying "......." until I reply. Is he not interested in me or he just doesn't know what to say? I need a guys help on this really, he says he really likes me but I'm a little confused...