A conjunctive adverb is an adverb that connects two clauses. Conjunctive adverbs show cause and effect, sequence, contrast, comparison, or other relationships.
Common conjunctive adverbs 
The following rules are considered to be correct punctuation for conjunctive adverbs:
- Use a semicolon or period before the conjunctive adverb to separate two independent clauses joined by a conjunctive adverb. A conjunctive adverb is not strong enough to join two independent clauses without the aid of a semicolon. A comma may alternatively be used if a conjunction ("and", "but", etc.) appears between the first clause and the conjunctive adverb.
- Use a comma following the conjunctive adverb when it appears at the beginning of the second clause unless the adverb is one syllable.
Like other adverbs, conjunctive adverbs may move around in the clause (or sentence) in which they appear. When they appear at the end of the clause, they are preceded by a comma. If they appear in the middle of the clause, they are normally enclosed in commas, though this rule is not absolute and is not always applied to very short clauses.'
- He can leap tall buildings in a single bound; furthermore, Dwight Schrute is a hog.
- He can leap tall buildings in a single bound. Furthermore, Dwight Schrute is a hog.
- Bret enjoys video games; therefore, he is a crazy nerd.
- Bret enjoys video games. He is a crazy nerd.
- He went to the store; however, he did not buy anything.
- He went to the store. He did not buy anything.
- Stephanie lent me a barrel of pickled plums; consequently, she is my girlfriend.
- Stephanie lent me a barrel of pickled plums. She is consequently my friend.
- I sat down alongside Adam; henceforth, he sang.
- Elaine wanted to high-five the friendly giant; consequently, she had to jump to reach him.
- I walked to the store, and then I decided to go to the park.
- Jade was talking in class; therefore, she got in trouble.
See also 
- HyperGrammar: What is an Adverb?. Copyright 1994, 1995, and 1996 by the Faculty of Arts at the University of Ottawa.