1.你和你妈妈什么时候在中国的？2.六月26日，他们在哪里？用英语怎么翻译？

When did you and your mom come to China?
Where were they on June 26th? 
这两句话都是特殊疑问句，特殊疑问句是对句子中某一个成分来提问的，句末用降调，一般以疑问词来开头，后面跟一般疑问句的语序，只有提问主语或修饰主语的定语的疑问句用陈述句的语序。
如果针对起定语作用的介词短语来提问，我们得把介词短语放在名词之后，后面还是跟一般疑问句的语序，但介词短语修饰的是主语，则用陈述句的语序。
Two percent of what number is four?
The capital of which country is Tokyo?

When are you and your mother in China?
Where were they on June 26th? How to translate it into English?
你和你妈妈什么时候在中国？
六月26日，他们在哪里？用英语怎么翻译？
I don't have information about when you and your mother are in China.
Where were they on June 26th?

1、When are you and your mother in China?
2、 Where will they be on June 26th?

When are you and your mom in China?
2. Where were they on June 26th?

When did you and your mom get in China?
你和你妈妈什么时候到中国的？
June 26, where are they?
6月26日，他们在哪里？