D.  The + adjective (without noun): The young, the old, the elderly, the rich, the poor, the homeless, the sick, the disable, the unemployed, the blind, the deaf, the injured, the dead: Always plural in meaning,
D1. The + Nationality: the English (the people of country), an Englishman
D2. not use The with names of people, and with the names of places: continents, countries, states etc., islands, cities, towns etc., mountains, but we use The, the republic of Korea, the UK.
D3. use The with plural names of people and place: People (the Lims: the Lim family), Countries (the Netherlands), Groups of islands (the Canaries), Mountain ranges (the Alps)
D4. the north but northern Korea, the Far East
D5. Most other buildings have name with The: The Sheraton Hotel, The Palace Theatre, The Guggenheim Museum, The White House
D6. no The: names of most city street – Queens Road, important institutions with two word – Harvard University. E.g. Buckingham Palace but the Royal Palace – Royal is an adjective but it is not a name
D7. Most newspapers and many organisations have names with The, but Names of companies, airlines are usually without The