Commas can be used to link the dependent clause of a complex sentence to its independent clause. For example:
Because it was raining, he did not go outside.
The semicolon can be used to connect two independent clauses instead of a period or to place a subordinating conjunction between two independent clauses. Example:
His shirt is red; however, his shoes are black.
A colon may be used to introduce something like a list. An example:
The following is the list of people that qualified:
