Answer to Question 1
Specifically, grammar is the study of language in terms of noticing regular patterns. These patterns relate to the functions and relationships of words in a sentence. They extend as broadly to the level of discourse and narrowly to the pronunciation and meaning of individual words. In your English courses, you may have been introduced to prescriptive grammar. This kind of grammar prescribes the correct ways in which to structure the use of written and spoken language. Of greater interest to psycholinguists is descriptive grammar, in which an attempt is made to describe the structures, functions, and relationships of words in language.
Answer to Question 2
Four areas of study have contributed greatly to an understanding of psycholinguistics:
Linguistics, the study of language structure and change
Neurolinguistics, the study of the relationships among the brain, cognition, and language
Sociolinguistics, the study of the relationship between social behavior and language
Computational linguistics and psycholinguistics, the study of language via computational methods
