Теория:

Study the information about collective nouns.
  
1. Words are called collective nouns if they refer to groups.

e.g. family, government
  
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2. We can use plural  and singular verbs with nouns: family, government, committee, company and jury.

These words also have regular plurals:
  
 Many families like spending time together.

3. We can use singular or plural verbs with nouns: the majority, the public, the youth.

Don’t put them into regular plural forms.
 
The public want (wants) to know about the government  and its policy.
 
4. We use only plural verbs with these collective nouns: cattle, the military, people, the police, vermin.

There are so many people in our world.
  
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Don’t put them into plural forms!
But! You should know that peoples means ‘national populations’:

The peoples of the Arab World have a common language.
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