There is no article:
With names of countries (if singular)
Germany is an important economic power.
He's just returned from Zimbabwe.
(But: I'm visiting the United States next week.)
With the names of languages
French is spoken in Tahiti.
English uses many words of Latin origin.
Indonesian is a relatively new language.
With the names of meals.
Lunch is at midday.
Dinner is in the evening.
Breakfast is the first meal of the day.
With people's names (if singular):
John's coming to the party.
George King is my uncle.
(But: we're having lunch with the Morgans tomorrow.)
With titles and names:
Prince Charles is Queen Elizabeth's son.
President Kennedy was assassinated in Dallas.
Dr. Watson was Sherlock Holmes' friend.
(But: the Queen of England, the Pope.)
After the 's possessive case:
His brother's car.
Engineering is a useful career.
He'll probably go into medicine.
With names of shops:
I'll get the card at Smith's.
Can you go to Boots for me?
1948 was a wonderful year.
Do you remember 1995?
With uncountable nouns:
Rice is the main food in Asia.
Milk is often added to tea in England.
War is destructive.
With the names of individual mountains, lakes and islands:
Mount McKinley is the highest mountain in Alaska.
She lives near Lake Windermere.
Have you visited Long Island?
With most names of towns, streets, stations and airports:
Victoria Station is in the centre of London.
Can you direct me to Bond Street?
She lives in Florence.
They're flying from Heathrow.
In some fixed expressions, for example:
on air (in broadcasting)