To such a great degree or extent, often used for emphasis, as in “so big” or “so tired.” It can also connect ideas to show result, like “It was late, so we went home.”
“So” comes from Old English “swā,” meaning “in this way” or “thus.” It is related to many similar little words in Germanic languages. Over time, English used it for degree, result, and emphasis.
“So” is a tiny word that does huge emotional work—listen to how people stretch it: “soooo happy,” “so done.” It also quietly glues arguments together in speech and writing. If you track your own “so”s for a day, you’ll see how much your thinking leans on it.
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