Not being a chemist I can't be certain but the 2 states are not mutually exclusive. Aren't there others such as suspension, solution, emulsion etc? Many materials exist in different forms at different temperatures (ice, water, steam). Others can be dissolved in liquids eg sugar, salt. Some can be suspended (wood fibre in water to make paper) and then fitered back out again. As a comment, I don't think milk is technically a liquid. It may be a suspension or emulsion!! As for glass, tell me more Einstein.....!!!!
If someone could give a proper definition of a liquid it would surely help.