Example sentences
tā他shàng上bān班qù去le了。
He went to work.
jǐ几diǎn点shàng上bān班？
What time do you start work?
About this word
上 is "to go to, to go on" and 班 is a work shift, so 上班 is "to go on shift", the everyday way to say "go to work". The rest of the schedule is built on the same 班: 下班 (get off work), 加班 (work overtime), 值班 (be on duty), 夜班 (night shift). 班 also means a school class, the same idea of a scheduled group. The verb is separable, so 上了一天班 works.
The story behind the character
上
A line with a short mark above it, meaning "on top of." This kind of character isn't drawn, it's indicated. Xu Shen wrote 上, 高也: "up, high." Fun fact: it used to be two lines, and the vertical stroke was added later to stop it being confused with the number 二.
班
班 is two pieces of jade with a knife between them. Two 王, which is really 玉, split down the middle by 刀. Xu Shen wrote 班, 分瑞玉也, "to divide a jade token." The ancients broke a jade tablet in two and each side kept half as proof of the agreement. So 上班, going to work, is literally reporting to your assigned piece.