着
RuleVerb + zhe: marks an ongoing action or a continuing state ("be in the state of V-ing").
Curiosity
Not "the door opens" but "the door is (standing) open" — how do you express the lasting state?
Intuition
zhe freezes the action like a held frame, keeping it "in that state." If le is the completion of a change, zhe is the resulting state staying on.
Visualization
Add zhe to ta zhan (he stands) → ta zhan zhe (he is standing). zhe attaches right after the verb.
plain action
他subject站verb
zhe added (ongoing state)
他subject站verb着着 (ongoing state)
Essence
Verb + zhe marks duration/state. It also links two simultaneous actions (xiao zhe shuo, "speak while smiling"). It often appears in existence sentences (qiang shang gua zhe hua, "a picture hangs on the wall"). Its nuance differs from the progressive zai/zhengzai (zhe stresses the continuing state).
Examples
门开着。
The door is (standing) open.
她笑着说。
She speaks while smiling.
墙上挂着一幅画。
A painting hangs on the wall.
Mini-quiz
Which expresses the lasting state "the window is open"?