"Not only" is a phrase used to introduce a statement, which is then followed by a second statement that is connected by "but also" or "but" (meaning "and also"). The second statement is usually stronger or more important than the first statement.
Here's why "not only" doesn't work in a negative sentence:
* Structure: "Not only" creates a parallel structure where both statements are positive.
* Meaning: The entire phrase implies an addition or emphasis, which clashes with the negative tone of a sentence.
Example:
Correct:
* *Not only* is he handsome, *but also* he's incredibly intelligent.
Incorrect:
* *Not only* is he *not* handsome, *but also* he's incredibly intelligent.
Instead of using "not only" in a negative sentence, you can use these alternatives:
* "Neither" + "nor"
* Example: He is neither handsome nor intelligent.
* "Not" + "and"
* Example: He is not handsome and he is not intelligent.
* "Neither" + "and"
* Example: He is neither handsome and intelligent.
Remember: "Not only" always implies a positive statement, even if it is followed by a negative one.