T HE ADVERBIAL CLAUSE
An Adverbial clause is a dependent or subordinate clause which modifies a verb,an adjective,or as an adverb in the principal or main clause.
The Adverbial clauses are introduced by the subordinate conjunctions.
The Adverbial clauses may be classified as adverbial clauses of
1 Time                               5 Result or Consequence
2 Place                               6 Concession or Supposition
3 Purpose                            7Condition
4 Cause or   Reason             8Comparison/Manner

1Adverbial clause of Time
The conjunction used are;  after, as ,as soon as,before,once, since, till, until, when ,whenever,while,as long as,no sooner, so long as, etc.
See the example;
Wait for  me till I come.
Look before you leap.