The part of linguistics that is concerned with the structure of language is divided into a number of subfields:
Phonetics - the study of speech sounds in their physical aspects
Phonology - the study of speech sounds in their cognitive aspects
Morphology - the study of the formation of words
Syntax - the study of the formation of sentences
Semantics the study of meaning
Pragmatics - the study of language use
Aside from language structure, other perspectives on language are represented in specialized or interdisciplinary branches:
Historical Linguistics
Sociolinguistics
Psycholinguistics
Ethnolinguistics (or Anthropological Linguistics)
Dialectology
Computational Linguistics
Psycholinguistics and neurolinguistics