When there is only one of something The earth, the sky, the city, the country (the suburbs), the sun, the moon, the
ground, the capital of France
Superlatives The most expensive restaurant…, the easiest way to do this…, the highest
number of…
”TV” does not take the article “the”; otherwise, we are talking about a specific Television. I watched the news on Television last night. (general)
Could you please turn up the television? (the TV in the room,
specific)
Nationality words The French, the English, the German, the Spanish, the Dutch
With adjectives to form a plural noun to refer to something in general The rich, the poor, the blind, the dead, the old, the unemployed, the homeless
Machines and inventions The telephone, the wheel, the bicycle, the car, the plane
Things when we refer to them in general (not a specific thing)