Cách sử dụng
Thirty is a number that comes after twenty-nine and before thirty-one. It is often used when we count or talk about quantities and amounts. For example, if you have thirty apples, it means you have 30 apples. You might also use thirty when talking about time, such as "I have to wake up at thirty minutes past six". It is important to remember that thirty is spelled with "th" and "irty", not "f" and "irty".