I don't understand why we need phrases and clause in the English language!
We need phrases because they add dimension to our sentences; provide detail. We also need clauses because without them we would write in sentence fragments.
So why does the English language need semicolons and colons?
Because semicolons allow us to join two sentences together without having to actually make two separate sentences. We use colons to separate complete sentences and words that clarify the sentence
Dependent sentence rely on independent sentences because dependent sentences are not complete on it's own while independents are so dependents need to be combined with independents by a subordinating conjunction.
Subordinating conjunctions have the role of transitioning two ideas into one sentence and illustrates purpose of an independent sentence.
What's the role of subordinating conjunctions?
When you make your own money, that's when you can buy it!
Until you're grown, I will pick your clothes for you.
I want this shirt, even though it cost $56!
You'll never let me do what I want, even if I'm 20 and out the house!
It's so cool though, whereas the other ones are so lame.
Using a semicolon combines two independent sentences. Example: The boy didn't get the shit; now he gets to watch a movie.
Colons are used to clarify words in a sentence. Ex: The boy didn't get the shirt so he did the following activities: watched a movie, got a haircut, and ate at his favorite pizza place.