Language comes before Grammar! Grammar is an attempt to describe a language. Hence, the language stands supreme and we as subordinates depend on the grammar of the language to access its virtues and mysticisms.
Communication Skills are made of Four Skills: Listening-Speaking-Reading-Writing. These four are divided into two: Receptive (Listening and Reading) and Expressive (Speaking and Writing). It is said that the one who is skilled in all these skills is the learner who has a good 'VOCABULARY'.