HSK 2
着
zhe助
aspect particle indicating action in progress or ongoing state
门开着，老师在里面。
Mén kāi zhe, lǎoshī zài lǐmiàn.
The door is open, and the teacher is inside.
Say it
Hold the button, say it, then let go.
Other HSK words sharing a character
Also free:
New in the HSK 3.0 word list at level 2.