So, I think I’m going a little crazy. I’ve been trying to figure out whether it’s okay to use the word “so” at the beginning of a sentence. Usually, when people start sentences with “so,” it’s acting as a conjunction, in which case it should, like “and” and “but,” go in the list of Words You Don’t Usually Start Sentences With. Beginning a sentence with a conjunction, as far as I can tell, should only be done for effect: the preceding full stop acts as a dramatic pause (a fermata, more or less) rather than the completion of a thought. “So” doesn’t seem to have the same dramatic effect as “and” or “but,” though, at least not when I read things out loud to myself.

In addition, you can almost always take the period before a sentence beginning with “and” or “but,” turn it into a comma, and — presto — you have a perfectly reasonable (if sometimes overly long) sentence. Not so much with “so.” Look at this couplet:

Killing demons replenishes this energy somewhat, but if you run out, it’s game over. So you not only have to kill all the demons to progress, you have to do it quickly.

Changing the period before the “so” to a comma turns the resulting sentence into an endless mess of a run-on. Dropping the “so” also makes it sound kind of awkward and disjointed. As it is, though, it’s clearly a single thought split into two sentences, which just doesn’t seem right. So is “so” an abused conjunction here, or something else?

Then there’s the “so” at the beginning of the first paragraph of this post. It’s clearly not a conjunction because there’s nothing before it to conjoin. I think that this use of “so” is more like “like” and “um” in speech, a sort of vocalized punctuation that can be safely dropped in writing.

Now, I’m a total idiot when it comes to grammar, so there’s probably some part of speech that I’ve never heard of that explains the use of “so” at the beginning of a sentence. If there is, will someone let me know before I drive myself nuts?