Study these sentences:
– The giraffe is the tallest of all animals.
– The bicycle is an excellent means of transportation.
– When was the telephone invented?
– The dollar is the currency (= teh money) of the United States.
In these examples, the … does not mean one specific thing.
The giraffe = a specific type of animal, not a specific giraffe.
We use the (+ singular countable noun) in this way to talk about a type of animal, machine, etc.
In the same way we use the for musical instruments:
– Can you play the guitar?
– The piano is my favorite instrument.
Compare a and the:
– I’d like to have a piano. but I can’t play the piano.
– We saw a giraffe at the zoo. but The giraffe is my favorite animal.
Note that we use man (= human beings in general / the human race) without the:
– What do you know about the origins of man? (not the man)
The + adjective
We use the + adjective (without noun) to talk about groups of people, especially:
the young the rich the sick the blind the injured the old the poor the disabled the deaf the dead the elderly the homeless the unemployed
The young = young people, the rich = rich people, etc:
– Do you think the rich should pay higher taxes?
– The government has promised to provide more money to help the homeless.
These expressions are always plural in meaning. For example, you cannot say “a young” or “the injured” for one person.
You must say “a young person,” “the injured woman,” etc.
Note that we say “the poor” (not the poors), “the young” (not the youngs), etc.
The + nationally
You can use the + nationality adjectives that end in -ch or -sh (the French / the English / the Spanish, etc.)
The meaning is “the people of that country”:
– The french are famous for their food. (= the people of France)
The French / The English, etc., are plural in meaning.
We do not say “a French / an English.”
You have to say a Frenchman / an Englishwoman, etc.
You can also use the + nationalities ending in -ese (the Chinese / the Sudanese / the Japanese, etc.):
– The Chinese invented printing.
But these words can also be singular (a Japanese, a Sudanese, a Vietnamese, etc.).
Also a Swiss (singular) and the Swiss (= the people of Switzerland)
With other nationalities, the plural noun ends in -s. For example:
– an Italian -> Italians
– a Mexican -> Mexicans
– a Thai -> Thais
With these words (Italians, etc.), we do not normally use the to talk about the people in general.