§13 and §14

The Augustinian picture - particularly the claim that 'every word in the language signifies something' even if partially true (true of a primitive language in some respects), doesn't tell us anything. You could use the claim 'every word in the language signifies something' to distinguish the words of a language from nonsense words - words without meaning (but this isn't the use Augustine makes of it).
Saying that every word in the language signifies something is as helpful as saying that 'every tool serves to modify something' - i.e. not very helpful at all.