Of things that are said, some involve combination while others are said without combination. Examples of those involving combination are: man runs, man wins; and of those without combination: man, ox, runs, wins.
Speech can be divided into two categories: speech involving combination and speech that does not involve combination. Speech that does not involve combination simply points to a concept such as man, ox, runs or calendar. Speech that involves combination adds more than one concept together. These need to be separated because Aristotle is going to make two sets of distinctions: one set will distinguish between kinds of concepts and the other set will distinguish how concepts are joined together.
Although I am speaking of concepts, we know that elsewhere Aristotle claims that concepts are always about things. So anything said of concepts can also be said about what those concepts point to. So joining two concepts together is another way of expressing two elements of reality together.
Next, Aristotle discusses divides the ways that one concept may be joinedto another into four.