The four key competencies in competent communication are linguistic competency, sociolinguistic competency, discourse competency and strategic competency, according to the National Capital Language Resource Center. Competent communication is the correct and appropriate use of language to achieve communication goals.
Linguistic competence is knowing the vocabulary, grammar and syntax of the language. Sociolinguistic competence is knowing how to use the language appropriately in the context of the setting, the topic, and the person one is communicating with. Discourse competence is knowing how to interpret the larger context of all the sentences put together. Strategic competence is knowing how to recognize and repair communication breakdown.