The phrasal verb 'sit in' is used more frequently in informal contexts than formal ones. It generally means to attend an event or a meeting but not actively participate, as in 'I will sit in on the class today.' This expression is commonly used in educational or professional settings where a person might observe or audit without taking an active role. Another usage context is music or performing arts, where a guest musician may 'sit in' with a band during a performance or rehearsal. Furthermore, it's sometimes used in political or activist contexts to describe someone participating in a sit-in protest, highlighting its flexibility across different domains. Despite its informal undertones, 'sit in' can be employed in formal writing or speech when describing specific scenarios, especially in discussions related to observation and participation.
A2
Elementary
1. To attend a meeting or an event as a spectator or participant, without actively participating.
I was allowed to sit in on the board meeting to get a sense of how decisions are made.
She often sits in on her brother's music lessons to learn something new.
2. To take part in an event, usually in the context of a protest or demonstration, by sitting down as a form of protest.
The students organized a sit-in to protest against the new policy.
Activists decided to sit in at the senator’s office until their demands were heard.