Time:
* After: We ate dinner after we finished cleaning.
* Before: I went to the store before it closed.
* Since: Since you left, I've been lonely.
* While: I studied for the exam while my roommate was sleeping.
* As: As the sun set, the temperature dropped.
* When: When I saw you, I was so surprised.
* Until: Until you told me, I had no idea.
* Whenever: Whenever I see you, I smile.
Cause and Effect:
* Because: I'm tired because I stayed up late.
* Since: Since you're leaving, I'll pack your bags.
* So that: I studied hard so that I could pass the exam.
* As: As you are the oldest, you should take responsibility.
Contrast:
* Although: Although I was tired, I went for a walk.
* Though: Though it was raining, we still went to the park.
* Even though: Even though I didn't want to go, I went anyway.
* While: While I like pizza, I prefer pasta.
* Whereas: Whereas you like spicy food, I prefer mild flavors.
Condition:
* If: If it rains tomorrow, we'll stay inside.
* Unless: I won't go unless you come with me.
* Provided that: We can go to the beach provided that the weather is good.
* In case: I packed an umbrella in case it rains.
Purpose:
* In order that: I studied hard in order that I could get a good grade.
* So that: I wrote down the directions so that I wouldn't get lost.
Comparison:
* As: You are as tall as your brother.
* Than: I am taller than you.
Other:
* Whether: I don't know whether I'll go or not.
* How: I'm wondering how you did that.
* Why: I'm curious why you said that.
This is not an exhaustive list, but it gives you a good starting point for understanding subordinating conjunctions. Remember that a subordinating conjunction introduces a dependent clause, which cannot stand alone as a complete sentence.