The following question got migrated from EL&U to ELL
If we look at this question as people who just give "yes, that's grammatical" or "no, that's not grammatical" type answers to users, then we might indeed want to move this question to ELL. However, if this is a site for linguists and serious language enthusiasts, this question belongs on this site here. The reason is that the syntax behind this question is quite sophisticated and is of significant interest to linguists.
It concerns why these sentences are grammatical:
- Bob is happy but Ben is not.
- Bob might be happy but Ben might not.
- Bob might be happy but Ben might not be.
But these sentences are ungrammatical:
- *Bob has been happy but Ben has been not.
- *Bob might be happy, but Ben might be not.
- *Bob wants to go, but Ben wants to not.
Want to know why? Erm, we'd better get this question reopened over here then - because this question will need several good answers from knowledgeable respondents to do it justice!
Please could we get this question back?