There are two sentences in my homework that I can't explain why they are ungrammatical. How to correct them?
1) The students heard the teacher's rumors about each other.
I guess there is something wrong about the word 'each other.' For me, this sentence is ambiguous too. But I'm not sure what exactly make this sentence ungrammatical.
2) John was preferred to have brought some snacks.
I have no idea for this sentence. Though I think the passive form of the verb "prefer" is not usually seen, it is grammatical.
Thanks for all your help.