How does L2 grammar knowledge develop?

How does L2 grammar knowledge develop? In order to address the main question, the essay will need to answer the following sub-questions. 1. What is grammatical knowledge? Identify what it is that the learner learns, and how this knowledge relates to knowledge of phonology and vocabulary. 2. How does grammatical knowledge relate to the ability to use the L2? 3. What are the external conditions (external to the mind of the learner) needed for grammatical knowledge to develop? Identify what kind of exposure and experience the learner needs to learn grammar. 4. What is the role, if any, of instruction in grammatical development? The paper should be divided into the following parts. Use the following as subheadings. i. Introduction/organization statement ii. Definition of grammatical knowledge iii. Relation of grammatical knowledge to the ability to use the L2 iv. External conditions needed for grammatical knowledge to develop v. Role of instruction in grammatical development iv. Conclusion