在场 zàichǎng to be present

to be present; to be on the scene

How to remember 在场: 在 at + 场 measure word for games and performances = to be present.

Characters

在场 (zàichǎng) means "to be present/on the scene," specifically at a particular event or incident.
Common in describing witnesses or bystanders: 当时我不在场 (dāngshí wǒ bú zàichǎng) - I wasn't there at the time.
Compare with 出席 (chūxí), which is formal attendance at a meeting or ceremony (你出席会议了吗?) - 在场 is about physically being at the location when something happened, often used in news, testimony, or accident reports.
Not used for routine "being at work" - it implies presence relevant to some specific event.