As the child moves into the mother tongue, Halliday's seven functions give way to:

1. Halliday's seven functions describe early, protolanguage use. 2. As the child moves into the mother tongue they give way to generalised metafunctions. 3. Metafunctions are the general modes of meaning in language. 4. Phonemic categories, tenses and private speech are not their successors. **Why not the others:** Phonemic categories are sound units, grammatical tenses are verb forms, and private speech is self-directed talk. _Source: Wikipedia, "Michael Halliday", section "Studies in child language development" (revision 1371974860)_