Do NOT use a semi-colon with a conjunction. Ex: Tom ate breakfast; and then he left. Use semi-colons before (and commas after) conjunctive adverbs that come between two sentences. Ex: Unemployment was ...

Ah, the adverb train station. If you want to find out about adverbs, there is no better place. An adverb tells you how something happens. Here is a train moving "quickly" on the track.