Conventions of Composition Rule 57

Rule: The word however is a conjunctive adverb. As such, it can't act as a conjunction. When used to join independent clauses, however should be preceded by a semicolon and followed by a comma. When used independently, however must be surrounded by commas and is best placed after the words most worthy of special emphasis or somewhere after the verb. Some other conjunctive adverbs (which follow the same punctuation and usage rules) are therefore, nevertheless, furthermore, moreover, in fact, consequently, hence, and accordingly. When using however as a conjunctive adverb introducing a subordinate clause, the whole clause (not the however) requires commas.

Examples:

Correct: He wanted to talk with Lenina; however, he was a real coward.

Correct: The Boers were brave fighters; they were unable, however, to prevent the ultimate victory of the English.

Correct: That sort of knot will slip, however tight you tie it.

Practice deciding if and how to punctuate these sentences:

1. However she decides to finish this game Hotchkiss will certainly win.
2. We wanted to go in fact we had already bought our tickets.
3. Mr. Bradley would love to give holidays more frequently however he knows the importance of patience.
4. The shoes weren't my size I tried however to shove my feet into them.

Resources for further explanation of how to punctuate conjunctive adverbs:

UNE Academic Skills Office's Using However

University of Wisconsin-Madison's The Writer's Handbook's Using Conjunctive Adverbs