1. How to convert years to American and British English words, how to write them out?

1.1. For years ending with three zeros:

• 1000 = the year one thousand, in both American and British English words;
• 2000 = the year two thousand, in both American and British English words;
• 3000 = the year three thousand, in both American and British English words;

1.2. For years ending with two zeros:

• 1700 = the year seventeen hundred, in both American and British English words;
• 1800 = the year eighteen hundred, in both American and British English words;
• 1900 = the year nineteen hundred, in both American and British English words;

1.3. If only the second digit is zero, there are three ways of writing the year out:

• 1059 = the year ten fifty-nine, in both American and British English words;
• 1059 = the year one thousand fifty-nine, in American English;
• 1059 = the year one thousand and fifty-nine, in British English;

• 2018 = the year twenty eighteen, in both American and British English words;
• 2018 = the year two thousand eighteen, in American English;
• 2018 = the year two thousand and eighteen, in British English;

Full article: how to write years out in American and British English words, using letters instead of numerals

1.4. If only the third digit is zero, there are two ways of writing the year out:

• 1609 = the year sixteen oh nine, in American English;
• 1609 = the year sixteen hundred and nine, in British English;

• 1902 = the year nineteen oh two, in American English;
• 1902 = the year nineteen hundred and two, in British English;

• 2108 = the year twenty-one oh eight, in American English;
• 2108 = the year twenty-one hundred and eight, in British English;

1.5. In general, when the first three digits of the year are different of zero, we write the first two and the second two digits as if they were single numbers:

• 1870 = the year eighteen seventy, in both American and British English words;
• 1878 = the year eighteen seventy-eight, in both American and British English words;
• 1970 = the year nineteen seventy, in both American and British English words;
• 1973 = the year nineteen seventy-three, in both American and British English words;
• 2110 = the year twenty-one ten, in both American and British English words;
• 2115 = the year twenty-one fifteen, in both American and British English words;

1.6. For years before 1000, we often say the first digit separately, then the last two as a single number, taking into account all the rules that were listed above:

• 474 = the year four seventy-four, in both American and British English words;
• 474 = the year four hundred and seventy-four, in British English words;

• 906 = the year nine oh six, in both American and British English words;
• 906 = the year nine hundred and six, in British English words;

• 43 = the year forty-three, in both American and British English words;
• 17 = the year seventeen, in both American and British English words;

Full article: how to write years out in American and British English words, using letters instead of numerals