Using "however"

Once in a while I'll get peeved enough by a widespread grammatical, spelling, or punctuation error that I'll carp about it here. For my very first such post, let's take the punctuation around "however."

From Technologizer contributor Ed Oswalt's piece on Microsoft's Kin:

Verizon is playing it off as part of a set of price reductions across its entire lineup, however most times when you see a price drop this early into a product’s lifespan, it has something to do with poor sales or not meeting certain goals.

Sorry, but that single comma before "however" is not correct. If you were to read the sentence out loud, you'd notice that when you reached "however," you paused longer than a comma would require. That's the sign that the all-purpose grammatical speed bump isn't sufficient.

The correct way to punctuate around "however" is with either a semicolon or period preceding it, and a comma following it:

Verizon is playing it off as part of a set of price reductions across its entire lineup; however, most times ...

or

Verizon is playing it off as part of a set of price reductions across its entire lineup. However, most times ...

If the whole thought is brief enough, a semicolon will do. For instance:

Most thought he was guilty; however, that was not the case.

Longer and more complex thoughts, like Oswalt's, should be punctuated as separate sentences. Even shorter ones can be punctuated as separate sentences for the purpose of emphasizing the contrary idea prefaced by "however":

Most thought he was guilty. However, that was not the case.

Another way that "however" can be used is illustrated -- incorrectly -- by another Technologizer posting, this time from David Worthington discussing some of Microsoft's plans for Windows 8:

There is however potential for an intelligent PC to really “know” its user and its environment, and it’s neat that Microsoft is looking into that.

This is a variant on the two-sentence usage of "however," and it could just as easily have been written thus:

However, there is potential for an intelligent PC to really “know” its user and its environment, and it’s neat that Microsoft is looking into that.

If, however, you want to use the construction Worthington attempted, you must frame "however" between commas:

There is, however, potential for an intelligent PC to really “know” its user and its environment, and it’s neat that Microsoft is looking into that.

And as long as we're on the subject, there's another use of "however" that doesn't require a trailing comma:

Money doesn't grow on trees, however much you may wish it did.

Here, "however" isn't serving to link ideas together in a conjunction-like way, as in prior examples. Rather, "however" is used in an adverbial sense to modify "much."