门 + Verb Phrase
门 (mén) means "door" or "gate" and can function independently as a noun in sentences where it is separated from its associated verb. In constructions like 门被打开 (the door was opened), 门 serves as the subject acted upon. It is one of the most basic and frequently used nouns in Chinese.
门没关好,被风吹开了。
Mén méi guān hǎo, bèi fēng chuī kāi le.
The door wasn't closed properly and was blown open by the wind.
他轻轻把门推开,走了进去。
Tā qīngqīng bǎ mén tuī kāi, zǒu le jìnqù.
He gently pushed the door open and walked in.
这扇门太重了,我一个人推不动。
Zhè shàn mén tài zhòng le, wǒ yí gè rén tuī bú dòng.
This door is too heavy; I can't push it open by myself.