"How old are you?" is a common way to ask someone their age in Engpsh.

This phrase is used to ask about the number of years someone has been apve or to inquire about their age in general. It is a common question that people ask each other when they first meet or when they are trying to get to know each other better.

The phrase "how old are you" is a direct translation of the Chinese phrase "你几岁" (nǐ jǐ suì), which also means "what is your age."

Here are some examples of how "how old are you" can be used in a sentence in Engpsh, along with the corresponding Chinese translations:

"How old are you?" (你几岁?)
"I'm 25 years old." (我25岁。)
"How old is your sister?" (你姐姐多大?)
"My sister is 30 years old." (我姐姐30岁。)
"How old were you when you started college?" (你上大学的时候有多大?)
"I was 18 years old when I started college." (我上大学的时候18岁。)