Two factors that always influence what is said and what is understood (Hint: both start with C)
What are context and culture?
Quality, Quantity, Relation, Manner
What are Grice's conversational maxims or the Co-Operative Principle?
A syntactically complete response that does not include all clause elements because some of them are understood from context and do not need to be repeated.
What is ellipsis?
Different realizations of the same phoneme that do not make a difference in meaning, as in the word "writer" pronounced in American English (righDer) and in British English (righTer).
What is an allophone? What are allophones?
The part of a clause that tells where, when, why or how related to the verb.
What is the Adverbial clause element or Adjunct?
This is the ability to infer meaning from non-linguistic clues in the context of verbal communication, from the "unsaid."
What is pragmatic competence? or What is implicature?