In first-language acquisition, a child first develops the ability to:

1. There are two main guiding principles in first-language acquisition. 2. One is that speech perception always precedes speech production. 3. So understanding comes before speaking, and writing comes much later. **Why not the others:** Writing, spelling and long sentences are all later productive skills. _Source: Wikipedia, "Language acquisition", section "introduction" (revision 1375526787)_