Noun + 堂
The noun 堂 (táng) means "hall," "main room," or "court," and it also appears in the compound 天堂 (tiāntáng, heaven/paradise). It is used as a suffix in many compound words referring to large rooms or institutions, such as 课堂 (classroom) and 礼堂 (auditorium). Its meaning depends heavily on the compound in which it appears.
下课后请大家回到课堂。
Xiàkè hòu qǐng dàjiā huídào kètáng.
After class, please everyone return to the classroom.
那座礼堂可以容纳五百人。
Nà zuò lǐtáng kěyǐ róngnà wǔbǎi rén.
That auditorium can hold five hundred people.
天堂和地狱只在一念之间。
Tiāntáng hé dìyù zhǐ zài yī niàn zhī jiān.
Heaven and hell are separated by just a single thought.