课外 + Noun
课外 (kèwài) means 'extracurricular' or 'outside of class.' It is formed from 课 (class) and 外 (outside), and is used as an adjective to modify nouns. For example, 课外兴趣课 means 'extracurricular interest class.'
学校有很多课外活动可以参加。
Xuéxiào yǒu hěn duō kèwài huódòng kěyǐ cānjiā.
The school has many extracurricular activities you can join.
他的课外时间都用来练钢琴了。
Tā de kèwài shíjiān dōu yòng lái liàn gāngqín le.
He spends all his free time practicing piano.
这本书是课外阅读的推荐书目。
Zhè běn shū shì kèwài yuèdú de tuījiàn shūmù.
This book is on the recommended extracurricular reading list.