Cardinal Numbers
Cardinal numbers are normally used when you:
count things: I have two brothers. There are thirty-one days in January.
give your age: I am thirty-three years old. My sister is twenty-seven years old.
give your telephone number: Our phone number is two-six-three, three-eight-four-seven. (481-2240)
give years: She was born in nineteen seventy-five (1975). America was discovered in fourteen ninety-two
Notice how we divide the year into two parts. This is the form for year up to 1999. For the year 2000 and on, we say two thousand (2000), two thousand and one (2001), two thousand and two (2002) etc.