Subject + 上 + (Subject) + 课
课 (kè) is a noun meaning "class," "lesson," or "course." It is used to talk about school subjects and individual class sessions. Common expressions include 上课 (to attend class), 下课 (class is over), and 语文课 (Chinese language class).
今天下午有两节数学课。
Jīntiān xiàwǔ yǒu liǎng jié shùxué kè.
There are two math classes this afternoon.
老师还没来,我们先不上课。
Lǎoshī hái méi lái, wǒmen xiān bù shàngkè.
The teacher hasn't arrived yet; let's not start class for now.
我最喜欢的课是历史课,特别有意思。
Wǒ zuì xǐhuān de kè shì lìshǐ kè, tèbié yǒu yìsi.
My favorite class is history class; it's especially interesting.