When are you supposed to use semicolons?

When a semicolon is used to join two or more ideas (parts) in a sentence, those ideas are then given equal position or rank. Some people write with a word processor; others write with a pen or pencil. Use a semicolon between two independent clauses that are connected by conjunctive adverbs or transitional phrases.

Before you make a stratement and after the statement i do belive.

Look at the passages where the author describes the isolation and insanity that dr frankenstein has