Pivotal sentences
In Chinese a 兼语句 (jiānyǔjù) is built from two verb phrases.
The object of the first verb is at the same time the subject of the second.
That is:
The first action is directed at a person, and then that person performs the second action.
Basic structure
主语 + 请 / 让 / 叫 + 宾语 + 动词 / 动词性短语
Subject + 请 / 让 / 叫 + person + verb / verb phrase
请qǐngto ask / to invite
让ràngto make someone do something / to let
叫jiàoto tell someone to do something
Important rule
Subject + Verb₁ + Object + Verb₂
The object belongs to the first verb, but is at the same time the doer of the second action.
For example:
我 + 请 + 你 + 帮个忙
I + ask + you + help out
Here 你 is:
the object of 请;
the subject of 帮个忙.
Examples
我想请你帮个忙
我wǒI
想请xiǎng qǐngwould like to ask
你nǐyou
帮个忙bāng ge mángto give a hand
Here 你 is the object of the first verb and the doer of the second action.
王老师让我们说中文
王老师Wáng lǎoshīTeacher Wang
让ràngto make someone do something
我们wǒmenwe
说中文shuō Zhōngwénto speak Chinese
Here 我们 is:
the object of 让;
the subject of 说中文.
妈妈叫孩子们回家
妈妈māmamum
叫jiàoto tell / to order
孩子们háizimenchildren
回家huí jiāto go home
Here 孩子们 is:
the object of 叫;
the subject of 回家.
Quick rule
主语 + 请 / 让 / 叫 + 宾语 + 动词
Meaning: someone is asked, told or made to do something.
请你帮个忙 — to ask you for help
让我们说中文 — to tell us to speak Chinese
叫孩子们回家 — to tell the children to go home