A few adjectives can be used as if they were nouns (e.g. after a an)
6 Adjectives
and can sometimes have a plural The listener mentally supplies the missing noun
/' ve got my medical on Thursday (= medical examination)
Don't be such a silly! (= a silly fool)
There s something the matter with the electrics in my car (= the
electrical system) Other words which are both adjectives and nouns are e g a black/blacks a red/reds a white/whites
6.12.2 'The' + adjective: e.g. 'the young' [> App 9]
Adjectives like the following are used after the never after a/an to represent a group as a whole e g the blind the deaf the living/the dead the rich/the poor the young/the old the unemployed. So the deaf means a group of people who are all deaf.
Andrew was sent to a special school for the deaf These adjectives are followed by a plural verb
You can always judge a society by the way the old are cared for. We can never use these adjectives on their own to refer to a single individual (Not * he is a young * * they are youngs *) If we wish to refer to single individuals, we must use an adjective + noun [> 6.6]
He s a young man with a lot of ambition They are young men Some of these adjectives may be modified e g the extremely poor the idle rich the super rich the young at heart Sometimes after e g both the can be dropped [> 3.28.6]
Both young and old enjoyed themselves at the party
The reference can be general or abstract in e g the supernatural to unexpected the unheard of the unknown So the unknown means that thing or those things which are not known
Scott s march to the South Pole was a journey into the unknown These are followed by a singular verb
The unknown is always something to be feared For the former the latter [> 4.11] For nationality adjectives used without nouns [> 3.19.2 App 49]