Adverbial clauses by semantic function

Function	Example
Time	When the bell rang, class ended.
Reason/Cause	Since it was late, we left.
Purpose	She whispered to avoid waking the baby.
Condition	If you call, I’ll answer.
Concession / Contrast	Although he was tired, he kept working.
Result / Consequence	She spoke so softly that we could hardly hear her.
Manner / Comparison	He treated her as if she were invisible.