The distinction between what we can say and what we do say

The distinction between significance and value

The distinction between unconscious picking up and conscious language study

All languages have common features

Behaviourism

Cognitivism

Scaffolding

Being give the rule or getting the rule from the examples

The learner's current ability

Acquisition vs. Learning

ZPD

Interlanguage

Deductive vs. Inductive processing

Universal grammar

Use vs. Usage

Constructing an internal grammar

Competence vs. Performance

Stimulus - Response theory