So - Because - But - Although

So - Because - But - Although

Observation:
1) We usually put a comma (,) before "so", "although" and "but";

2) "Though": colloquial form for although. It's not used in the beginning;

3) "So": It can also be used with a different meaning, when it's used to intensify adjectives.
     E.g.: It's so beautiful!