1)Before common nouns in the singular and the plural used in a particular sense: The sportsmen went to the starting line. Do you remember end of the story? We have breakfast in the kitchen. We keep the floor clean.
2) With unique objects: the sun, the moon, the sky, the earth, the world, the ground, the past, the singular, etc.: the sun was getting warmer.
3)John is the youngest boy in our form. The third lesson is physics.
4)The merry love to dance. The wounded were taken to another hospital.
5)The North, the South, the East, the West, the northwest wind, etc. Life in the North (noun) is hard. The tourists went north (adverb) and reached Cēsis. But: From East to West, from North to South.
6)With the names of musical instruments: My friend plays the violin. He can’t play piano.
7)Before nouns qualified by the words same, very, following, only: He came on the same day. He returned in the very evening. Learn the following words. I’m the only child in our family.
8)With the names of organization and parties: the Labour Party, the Royal Society, the Common Market, the United Nations, etc.
9)The radio, the press, the newspapers, the train, etc.
10)The Latvians, the Poles, the Americans, the peasantry, the bourgeoisie, etc.
11)The tiger is a beautiful animal. The rose is the queen of flowers.
12) With names of rivers, seas and oceans, canals, mountain rages: the Alps, public institutions, newspapers, ships, some countries the USA, the Crimea, the Netherlands, the Congo, the Philippines, the West Indies, surnames in the plural denoting the hole family: The browns, The Wilson are at home.