Could you tell me "He sits opposite to me."? Could I say"He sits opposite me." and delete the "to"?
Are they both right?

Question

Answer

Yes - you need to delete the 'to'.  The first sentence is not correct.

Answer

opposite as a prep. it  means on the other side of a particular area from sb/sth eg. I sat opposite him during the meal.(on the other side of the table) eg. The  bank is opposite the supermarket.( on the other side of the road)