Adverbial clauses are clauses connected by adverbs.
There are three types of adverbial clauses in Chinese:
(i) adverbial clauses with adverbial connectors
他不但很認真,而且也很努力
t¯a b´ud`an h˘en r`enzh¯en, ´erqi˘e y˘e h˘en n˘ul`ı
( He is not only very serious but also works very hard.)
(ii) adverbial clauses in the form of relative clauses
當我回家的時候,路上出了車禍
d¯ang w˘o hu´ı ji¯a de sh´ıh`ou, l`u-sh`ang ch¯u-le ch¯e-hu`o
( When I returned home, (there was) a traffic accident on the road.)
(iii) Adverbial clauses with parallel and repeated Connectors of both clauses
這篇文章又臭又長
zh`e-pi¯an w´enzh¯ang y`ou ch`ou y`ou ch´ang
(This article is both malodorous and long.)
Reference: Chinese: a linguistic introduction by Chao Fen Sun