Study information about the definite article.
We use the in these situations:
1. nouns are unique.
Haven't you been to the Acropolis yet?
Рис. \(1\). The Acropolis
2. names of cinemas, museums, hotels, theatres, newspapers, ships.
I want to go to the National Gallery.
Рис. \(2\). The National Gallery
3. names of rivers, seas, groups of islands/states, mountain ranges, deserts, oceans.
The Thames is the longest river in England.
Рис. \(3\). The Thames
4. names with of.
The Tower of London is the most wonderful sight.
5. musical instruments.
Can you play the piano?
Рис. \(4\). The piano
6. names of people/families/nationalities in the plural.
The English are considered to be reserved.
7. titles without proper names.
The Queen, the President
Shaun Jeffers Shutterstock.jpg
Рис. \(5\). The Queen
8. adjectives used as plural nouns.
the rich, the poor
9. the superlative degree of adjectives/adverbs.
She is the friendliest person I've ever met.
Рис. \(6\). Friendly  
10. when it is clear which thing or person we mean.
Can you tell me the time, please?
Рис. 5. The Queen, Shaun Jeffers /