The verbs sit and set are commonly confused and misused, but the difference between them is similar to the difference between lay and lie – and maybe even easier to understand. The similarity between each set of words lies in the fact that one verb is transitive and needs a direct object, while the other verb is intransitive and can stand alone. Another similarity: if you use the wrong one, you are liable to sound like an uneducated person. “So why don’t ya set a spell, if that idea lays well with ya?”
To illustrate, let me tell you a short, repetitious, but grammatically correct story about a tired man:
The Tired Man
The tired man sets his burden down on the floor. He lays his burden down. Then he sits down in a chair. He sets his hindquarters1 right down on the chair and he rests himself. He goes to sleep.
1 The word hindquarters is a polite or euphemistic term for the part of the human body upon which humans usually sit.
Notice that the man sets his burden somewhere. (Is it a backpack? a box? a board? Mysteriously, the author doesn’t say). The man doesn’t sit his burden. Sit, like lie, is intransitive and can never take an object. His hindquarters, though a part of himself, are an object and can be set anywhere they are comfortable, within reason.
You can set a thing anywhere you like, but you can only sit comfortably in a limited number of places. A chair is the most common place to sit. You can set something on a shelf, but unless you are very small, you can’t sit on a shelf.
If you are very large and strong, like King Kong, you can set a person somewhere, like Fay Wray. But it isn’t polite. King Kong, after all, was a beast and a monster. Most of us only set inanimate objects that are smaller than us, because living things usually object to being set somewhere, at least, the ones . That may help you remember the distinction. Another memory aid: set means the same thing as put. If I said, “I’m going to put on the table,” you might rightly ask, “Pardon? Put what on the table?” Set is the same way – it needs an object.
Both sit and set, however, are usually accompanied by a prepositional phrase, which is sometimes mistaken for an object. It’s correct to say, “I sat,” without any object, but your reader may want to know where you sat, to better visualize the scene. Likewise, it’s correct to say, “Let me set the scene for you,” meaning, “Let me explain the situation before I go on talking,” but it would seem odd to say, “I set the gold.” Your reader will be burning to know, “Where did you set it?”