1. He is unhappier than Tom.
2. He is more unhappy than Tom.
3. Your room is untidier than mine.
4. your room is more untidy than mine.
[What about these sentences? Which sentences are grammatical?]
2. He is more unhappy than Tom.
3. Your room is untidier than mine.
4. your room is more untidy than mine.
[What about these sentences? Which sentences are grammatical?]