B. Types of adverbial clauses
B1. Contrast clauses: although; though; even though; while
B2. Reason clauses: because; since; as
B3. Place clauses: where; wherever; everywhere
B4. Purpose clauses: so that; so; because + want
B5. Result clauses: so that; so ~ that; such ~ that
B6. Time clauses: when; before; after; since; while; as; as soon as; by the time; until
B7. Conditional clauses: if; unless; provided (that); as long as )