language = the abstract, unconscious system in our mind/brain

Acquisition = the process of getting language into our mind/brain 

​COMMUNICATION = THE EXPRESSION, INTERPRETATION, AND NEGOTIATION OF MEANING WITH A PURPOSE IN A GIVEN CONTEXT

"Simply put, learners 'get grammar' by attending to comprehensible meaning-bearing input; they don't build a linguistic system up over time as a matter of oral practice" (vanpatten, 1994).

"WE ACQUIRE LANGUAGE WHEN WE UNDERSTAND WHAT PEOPLE TELL US OR WHEN WE UNDERSTAND WHAT WE READ. AND THERE IS NO OTHER WAY IT CAN HAPPEN" (KRASHEN, 2013).