Krashen's term for conscious knowledge of rules gained through formal teaching:

1. Krashen says there are two independent ways to develop language skills. 2. The conscious one, as in school, stores language forms as rules and grammar and often involves error correction. 3. He calls this conscious process **learning**; the subconscious one is acquisition. **Why not the others:** Acquisition is the subconscious route. The affective filter and the natural order are other hypotheses, not names for conscious knowledge. _Source: Wikipedia, "Input hypothesis", section "Acquisition-learning hypothesis" (revision 1380165607)_