§1 "When they (my elders) named some object, and accordingly moved towards something, I saw this and I grasped that the thing was called by the sound they uttered when they meant to point it out. Their intention was shown by their bodily movements, as it were the natural language of all peoples: the expression of the face, the play of the eyes, the movement of other parts of the body, and the tone of voice which expresses our state of mind in seeking, having, rejecting, and avoiding something. Thus, as I heard words repeatedly used in their proper places in various sentences, I gradually learned to understand what objects they signified; and after I had trained my mouth to form these signs, I used them to express my own desires." (Augustine, Confessions, I. 8.)
These words, it seems to me, give us a particular picture of the essence of human language. It is this: the individual words in language name objects --- sentences are combinations of such names.---In this picture of language we find the roots of the following idea: Every word has a meaning. This meaning is correlated with the word. It is the object for which the words stands.
Augustine does not speak of there being any difference between kinds of word. If you describe the learning of language in this way you are, I believe, thinking primarily of nouns like "table", "chair", "loaf", and of people's names, and only secondarily of the names of certain actions and properties; and of the remaining kinds of word as something that will take care of itself.
Now think of the following use of language: I send someone shopping. I give him a slip marked 'five red apples'. He takes the slip to the shopkeeper, who opens a drawer marked 'apples'; then he looks up the word 'red' in a table, and finds a colour sample opposite it'; then he says the serious of cardinal numbers ---I assume that he knows them by heart--up to the word 'five' and for each number he takes an apple of the same colour as the sample out of the drawer.----It is in this and similar ways that one operates with words.----"But how does he know where and how he is to look up the word 'red' and what he is to do with the word 'five'?"-----Well, I assume that he acts as I have described. Explanations come to an end somewhere.---But what is the meaning of the word 'five'?---No such thing was in question here, only how the word 'five' is used.