On the subject of semicolons, while it's true that you shouldn't use them if you haven't been properly taught, here are a couple general guidelines.

A semicolon can help combine two related sentences into one sentence. It can also take the place of "and" or "because" (rarely "but") in a sentence. For example:

Two sentences - We took our dog to the vet. He was sweating profusely.

One sentence - We took our dog to the vet because he was sweating profusely.

Semicolon sentence - We took our dog to the vet; he was sweating profusely.
Hope that helps!

EDIT: Heald fixed his, I no longer need to correct it.