Prescriptive vs Descriptive Grammar

Rules from authorities vs. how people actually speak.

Examples

• Singular they is widely used.

Key rules

• Prescriptive grammar sets out rules that some authorities recommend
• Descriptive grammar records how people actually use language
• Both are useful: know the standard form and recognise how people speak

Common mistakes

• Singular they is always wrong → Singular they is widely used and accepted in many contexts
• Ain't is never used → Ain't is common in some dialects

Use cases

• Understanding grammar books
• Listening to varied speakers
• Academic study of language