Always wanting to be helpful, I've developed this quick lesson for the proper use of our favorite little conjunction, but. Students! Pay attention:
The first step is to recognize that but is most always used as a conjunction. See this nifty old video for a sing-a-long lesson. As a conjunction (distinguished by its function... go ahead, sing now) it connects words, phrases, clauses and even sentences. It joins--and as you may know, joining is in the root of the very word conjunct (with connect).
The next step in recognizing but as a conjunction is to ask how it connects or joins the two seperate parts. Is it in comparison? Contrast? Disagreement? Clarifying? Ask yourself what but brings to the meaning.
Then you should understand the proper written grammatical rules. You can click here to see a little primer I'd posted for you. Most of the time it is proper to add a comma before your but. It is not proper to have a comma after your but. But, (note the post-but comma?) it is okay to put a comma after your but if you're trying to communicate inflection or make an artistic impression in your writing. Get it? In that previous sentence, for instance, I wanted you to pause gently after you read but--hence the comma. See how artistic I am? This is perhaps the hardest written grammar rule concerning but to wrap your head around, because it's all about style. Oh, and if this isn't confusing enough for you, know that it is becoming more and more acceptable to omit the comma altogether where but is concerned. Style, once again.
Know also that it is entirely okay to begin a sentence with but. For years Grammarians insisted the opposite, but it's grown in acceptance. Use but as a conjunctive adverb--like the word 'however'--to start a sentence. But beware. (Note that I started that little sentence with but as a conjunctive adverb?) Starting too many sentences with the word but and people may start to think that you're just disagreeable. You're not disagreeable, are you?
One last thing to know is that but can occasionally be used as a preposition. Prepositions, you'll recall, show relationship and positioning. In, on, over, under, beside, through--you get the idea. But is technically a preposition when it is used like the word except. Everyone but Sally understood. I say tecnically, because in effect but still functions conjunctively too. You have the prepositional relationship and positioning--Sally's on the outside looking in. You also have the conjunctive joining--everyone but Sally. The key to recognizing this really is the word except. If you can substitute except for the but then it's a prepositional usage. Got it? Now I ask you: Why would anyone want to substitute anything for their but?
You can take this quiz if you want some practice. Answers are in the comments section.
Your assignment, class: Be on the lookout (and listen) for the word but. See how fast you can identify it in conjunction, conjunctive adverb or prepositional use. See how often you can spot it improperly punctuated. Call it out! Stand up for the proper care and handling of our little three letter darling!
