Sort each statement about language: descriptive (how people speak) or prescriptive (how someone says they should)?

Descriptive: Many Londoners pronounce "th" as "f", Double negatives mark emphasis in this dialect, Younger speakers here are dropping the case endings

Prescriptive: Never end a sentence with a preposition, "Ain’t" is not a real word, Say "whom" wherever it is grammatically licensed

Linguistic anthropology is descriptive: dialects are data, not errors. Prescriptive rules are themselves data too, evidence about which groups hold the social power to define "correct."