ADVERBIAL CLAUSE

An adverbial clause is a clause that functions as an adverb. In other words, it contains subject (explicit or implied) and predicate, and it modifies a verb.

The following are the kinds of adverbial clause :
1. Clause of time 
Subordinate conjuction : when, before, after, since, while, as, as long as, until,till. 
e.g : She was reading a book while the dinner was cooking. 

2. Clause of place
Subordinate conjuction : where, wherever, anywhere, everywhere
e.g : Wherever possible, the illustrations are taken from literature.

3. Clause of reason
Subordinate conjuction : because, since, as, given
e. g: I couldn't feel anger against him because I liked him too much.

4. Clause of condition
Subordinate conjuction : if, unless
e. g: If they lose weight during an illness, they soon regain it afterwards.

5. Clause of contrast
Subordinate conjuction : although, though
e. g: I used to read a lot although I don't get much time for books now

6. Clause of purpose
Subordinate conjuction : that
e. g: They had to take some of his land so that they could extend the churchyard.

7. Clause of manner
Subordinate conjuction : as if
e. g: He looks as if he needs more sleep.

source :english-hilfen