The phrasal verb "sit in on" is predominantly used in informal to semi-formal contexts, though it occasionally appears in formal settings. It generally refers to the act of attending a meeting, class, or event as an observer or guest, without taking an active role or being officially involved. This phrase is commonly used in educational settings, where a person might "sit in on" a lecture to learn or evaluate without being a registered participant, or in professional environments where someone might "sit in on" a meeting to gain insight or for training purposes. Despite its informal roots, its frequent use across various contexts has lent it some acceptance in more formal documents or speech, especially where the expectation is clearly observational rather than participatory. It's an accessible phrase that underscores the passive attendance nature, useful for learners, visitors, or even potential participants who are assessing whether to get involved actively in the future.
B2
UpperIntermediate
1. To attend a meeting, class, or event simply as an observer.
I decided to sit in on the lecture to see if the professor's teaching style would work for me.
She is sitting in on the board meeting to learn more about how the company makes decisions.
The new employee sat in on the training sessions to get a sense of what the team does.
He often sits in on band rehearsals to offer suggestions and feedback.
They allowed us to sit in on the negotiations to better understand the process.