when there's only one of something
with general singular nouns
when you mention something for the first time
with general plural or uncountable nouns
with phrases like: at home/at work, go home/to bed/to work, next/last (week, month, etc.)
with specific nouns
with buildings in a town
when it's clear who or what somebody is
with prison, church, school, hospital, university if you're thinking about the institution and its purpose
mountain ranges, rivers, seas, canals, deserts, and island groups
roads, streets, parks, bridges, shops and restaurants
most countries, continents, regions, states, islands, provinces, towns, cities
when you say what somebody or something is
names of theatres, cinemas, hotels, galleries and museums
individual mountains and lakes
