I kind of thought he would be like that at school. He's the same at home.
I knew it. That's how he behaves at home too.
ーI kind of thought he would be like that at school. He's the same at home.
「彼は学校でもそうじゃないかとちょっと思っていました。我が家でも同じです。」
I kind of thought he would ... で「彼は…だろうとちょっと思っていた」
ーI knew it. That's how he behaves at home too.
「やっぱり。家でも同じような態度です。」
I knew it. で「やっぱり」
behave で「振る舞う・〜のような態度をとる」
ご参考まで!