swallowing is a very complex movement that is both cortically and reflexively mediated. There are three basic stages to swallowing: oral, pharyngeal and esophogeal. The oral stage is really the only voluntary stage and we control the movement of the food into our mouths and our chewing patterns (even though they become very automatic and we don't really think about it). Difficulty can arise at any stage and can be related to muscle weakness in the cheeks, tongue and throat that result in poorly chewed food and pocketing that leads to choking and aspiration as well as halitosis and spillage. If there is damage to the cranial nerves that control the tongue, facial muscles and pharyngeal muscles, there can be an uncoordinated swallow or minimal swallow reflex. You can have a swallow evaluation done by an occupational therapist, neurologist, or speech therapist (they usually work as a team) to determine what the problem is and what the treatment options are. Good luck!
