1. Because: Indicates a reason or cause.
* Example: *We stayed inside because it was raining.*
2. Although: Indicates a contrast or concession.
* Example: *Although she was tired, she finished her work.*
3. Since: Indicates time or cause.
* Example: *Since you're here, let's have some coffee.*
4. While: Indicates simultaneous events or contrast.
* Example: *While I was cooking, he was cleaning.*
5. If: Indicates a condition.
* Example: *If you study hard, you will succeed.*