1.- You use "the"
with singular nouns and when the person you are talking
to knows the thing or person you are talking about:
I spoke to the Queen yesterday
(the Queen of England)I left the food in the fridge
(the fridge in my house)I bought two skirts and a watch. The
skirts were expensive (the skirts
I bought)
Have you washed the glasses?
(the glasses we have been using)
2. You use "the" when there is only one of
something:
Madrid is the capital of Spain
The earth goes round the
sun
3.You use "the" with a singular noun when you
want to make general statement.
The book is very interesting
However, you do not use "the" with plural nouns
to make a general statement 4.- We say:
The sky / The sea / The ground
/ The country / The environment / The cinema / The theatre
5.- We do NOT say:
The breakfast / The lunch
/ The dinner
Example:
What did you have for breakfast?