The difference is that grammar rules are both superficial and sub- iective-in the sense that they purport to describe regularities in one person's behavior as observed by ,orn"ott" else-while grammar-tactics are obiec- tive in the sense that they are defined to be the underlying processes that actually produce speech' Although it may be more difficult to discover iust what those processes do, it is better to speculate on how language is produced and used than merely to describe its observed, external forms