Mad Libs should not be used to teach grammar. Now some would argue that providing a context for incidental learning is, indeed, teaching. Some may suggest that many forms of incidental learning, such as vocabulary acquisition through independent reading are essential. Fair points, but incidental learning is effective and necessary in some academic areas, but not in others. Grammar, or the structure of our language, is not conducive to incidental learning. To argue that we should teach the structure of our language in an unstructured way is downright silly.