Even though there's already a similar question here, mine is a bit different. I want to know if they can be used interchangeably.
This question came to my mind, actually when I was playing Duolingo. I did the Spanish course, and the original Spanish sentence was:
Mi vida no es mejor que la tuya.
I used Google Translate and the translation is:
My life is no better than yours.
The key answer (from Duolingo) is
My life isn't better than yours.
However, my answer was accepted by Duo. Does that mean both can be used interchangeably?
P.S. Please, note that sometimes, Duolingo gives the translations based on the literal meaning from the original language rather than idiomatic English. (That's why I doubt it)
Best Answer
They do not have precisely the same meaning, but in most cases there is no effective difference in their literal meaning.
means that it is not the case that my life is better than yours. It is a simple negation.
means that the degree of goodness in my life is not higher than in your life. It is a scalar negation.
But in use, there will also be a pragmatic distinction. No better than is a relatively unusual construction, and when it is used, it tends to have an implication of judging something or somebody, or that the thing compared is not high in the value of the comparison.
So here, it suggests that your life is not very good, but mine is just as bad. This implication is not there in the not case.