作主【zuò zhǔ】
decide; take the responsibility for a decision
[动短]对某件事作出决定并负全责

这是我的房间,怎么摆放家具由我作主。
This is my room and it is up to me to decide the arrangement of the furniture.
坐【zuò】
1. sit 2. to take (a bus, airplane etc. ) 3. (of a building) have its back towards
[动]1、把臀部放在椅子或其他物体上支撑身体重量 2、乘、搭 3、(房屋)背对着某个方面

我只喜欢坐在椅子上看书。
I only like reading in the chair.

坐出租车是到那里最方便的办法吗?
Is taking a taxi the most convenient way to get there?

我家的新房子坐北朝南。
My house faces south.
坐班【zuò bān】
keep office hours; work in one’s office during office time; be on duty
[动]每天规定时间上下班(多指坐办公室);值班

我无法摆脱单调的坐班工作。
I can't get off the office treadmill.