Did you forget how old you are?

你忘了自己多少岁吗？

How old are you, my dear friend?

亲爱的朋友，你几岁了？

I'm nine. How old are you?

我九岁。你几岁了？

How old is the old man?

这位老人有多大年龄了？

How old were you then?

你那时多少岁？

How old was the boy?

那个男孩几岁？

Look how old I look!

看我看起来多年老！

How old do I look?

我看起来是有多老？

How old was Bob when he started riding horses?

鲍勃几岁开始骑马？

How old was Du when she did a little research to solve the problem?

Du 在几岁时做了一些调查来解决这个问题呢？

If you ask Westerners how old they are, they would feel offended by such personal questions.

如果你问西方人他们多少岁了，他们会觉得自己被这些私人的问题冒犯了。

How old is she—seventy odd?

她多大年纪？七十出头？

Now let me see—how old is she now?

让我想一想，她现在多大了呢？

How old is this building?

这座建筑已有多少年了？

How old is your son now?

现在你儿子有多大？

How old are you now?

你现在多大了？

How old is she?

她有多大了？

Assuming (that) he's still alive, how old would he be now?

假定他还活着，现在有多大年纪了？

How old are these sea turtles?

这些海龟有多大了？

How old are you? I am nineteen.

你多大了？我十九岁了。

How old is the woman's daughter?

这位女士的女儿多大了？

How old are the students in your class?

你们班的学生多大了？

How old will Beijing Opera be in 2020?

到2020年，京剧将有多少年历史？

For example, they can guess if you are male or female, how old you are, and your interests.

例如，他们可以猜出你是男是女，还有你的年龄和兴趣。

How old is your brother?

你弟弟多大？

How old is your mother?

您母亲多大岁数了？

How old are these dogs?

这些狗多大了？

How old is your niece?

你的侄女多大了？

Jane, how old are you?

简，你多大了？

How old is painting?

绘画的历史有多久？