However, there are a few things to consider:
* "So" as a conjunction: If "so" is used to connect two clauses, it's perfectly acceptable to end a sentence with it. For example: "I was tired, so I went to bed."
* "So" as an adverb: If "so" is used to emphasize a degree or intensity, it's also grammatically correct to end a sentence with it. For example: "I was so tired, I could barely keep my eyes open."
* Informal vs. Formal: Ending a sentence with "so" is more common in informal speech and writing. In formal writing, it's generally preferred to use a more sophisticated way to conclude a sentence.
Overall, while ending a sentence with "so" isn't grammatically incorrect, it's important to consider the context and style of your writing.