This question accepts both "No, better not." and "No, not better." as an answer.
To me, the first sentence sounds like "No!, you better not do that!" and while as the second sounds more like "No, this ( book, movie, or whatever ) is not better.".
Does this sentence apply to both of those situations?
It's also a problem because if it's being used as an admonition "better not" is rarely used without describing who shouldn't. As in "No, we'd better not" or "No, you'd better not" "No, better not" just sounds like unidiomatic English to me. Any other native English speakers have a different take?
"No, it isn't better" does not mean the same as "No, better not." Better not is roughly the same as saying "We shouldn't".
"No, it isn't better" example:
- Would you say Pepsi is better than Coke?
- No, it isn't better.
"No, better not" example:
- I think we should beat up Harper.
- No, (we) better not. We'd likely get arrested.
Hope that helps!
It's only bessere if it comes before a noun, and based on the gender of that noun and whether it has a definite article alongside it.
i.e. "Das ist eine bessere Katze", but "Das ist ein besseres Auto"
"Das sind bessere Autos", but "Ich fahre mit einem besseren Auto"
Also, "Das Auto ist besser" (No ending because it's not an attributive adjective)
Here's a useful resource: