I already wrote a post about age. In the previous post, I wrote about when to use 几岁 and 多 大. Link can be found here: https://dominiksymonowicz.com/2018/07/26/difference-between-age-characters. In this post, I will talk about asking for age in the Chinese culture.
There is an interesting difference between the Western and Chinese culture with regards to age. In western culture, it is considered impolite to ask an older woman for age. In the Chinese culture, it is common to ask older people for their age as it shows respect for their knowledge and health. There are 3 ways to ask for age. For little kid, you ask 你几岁？For adults 你多大？. For older people, you usually do not ask for age, but you ask which year there were born 你是哪年生的?