Halliday's first four functions mainly help a child satisfy:

1. The first four functions are instrumental, regulatory, interactional and personal. 2. They help the child to satisfy physical, emotional and social needs. 3. The last three functions are heuristic, imaginative and representational. 4. Moral duties, examinations and writing are not the purposes named. **Why not the others:** Moral and civic duties, examination demands and writing requirements are not the needs Halliday names. _Source: Wikipedia, "Michael Halliday", section "Studies in child language development" (revision 1371974860)_