1. that is so, that is right, it looks to me, that's my impression

interjection (kandoushi) polite (teineigo) language

2. people say that, it is said that, I hear that

expressions (phrases, clauses, etc.) polite (teineigo) language

こちらこそ そうです ちがいます わかりません どうもすみません ～さん ～ちゃん ～君

tbd