Origin of geotagged tweets w/o exact location from Streaming API



if a georeferenced tweet is created w/o the exact geolocation attached a user has one of the two choices: he can select a location from one of the proposed entries in the list or he can type in a place by himself (which could basically be anywhere in the world, right?).
Is there a way to see this difference in tweets I am crawling via the Streaming API?