1. I feel alone in the living room.

2. I feel lonely in the living room.
3. I feel lone in the living room.
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Are #1 and #2 the same? #3 is wrong, right?
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4. He is driving on a lonely road.
5. He is driving on a lone road.
6. He is driving on an alone road.
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Are #4 and #5 the same? #6 is wrong, right?

1. I feel alone in the living room.

2. I feel lonely in the living room.
3. I feel lone in the living room.
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Are #1 and #2 the same? #3 is wrong, right? You are correct, yes.
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4. He is driving on a lonely road.
5. He is driving on a lone road.
6. He is driving on an alone road.
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Are #4 and #5 the same? #6 is wrong, right? You are correct that 6 is wrong, but 4 and 5 are not the same. 5 means that there is only one road. 4 means there are no other cars on the road.