Occasionally, I run into students who don’t seem to realize that sentences end.
They talk about one topic and then head off in a completely different direction. Sometimes they return to the original topic before gracing the sentence with a period. The longest sentence I’ve ever seen was 267 words. No kidding. Did the person simply forget the periods? I wish.
So how do you know if your sentence is too long-winded? Read it out loud. If you need to come up for air, the sentence is longer than it should be.
This is not a marathon, folks. You should not be trying to outlast your reader. The person who stays in the sentence the longest is not the winner! Do not try to confuse the reader or obfuscate the topic at hand. Emulating a politician who is muddying the rhetorical waters should not be your goal. (Please note that the previous sentence was a passive voice construction, in case you are looking for an example. To write that in active voice, I would write “It should not be your goal to emulate a politician who is muddying the rhetorical waters.” I included it as written for your reading enjoyment.)
Instead, write sentences that make sense, clearly explain whatever it is that you are talking about, and stick to the topic at hand. This is also not a sprint, where you write choppy sentences that only hang together by the smallest of threads. Make your point, do it well, and get on to the next topic at hand.