This document discusses several key topics in linguistics, including:
1. Descriptive linguistics examines the sounds, words and rules of language through concepts like phones, phonemes, morphology and syntax.
2. The International Phonetic Alphabet provides symbols to represent the sounds of human language.
3. Languages have biological roots in structures like the brain and vocal tract that enable speech.
4. Language has properties like arbitrariness, productivity, displacement and cultural transmission that distinguish it from animal communication systems.