Which class was the most fun and which one was the most boring today?
Was the teacher nice to you?
Were you able to have a good time with your friends?
ご質問ありがとうございます。
"Which class was the most fun"＝「どのクラスが一番楽しかった？」
"and which one was the most boring today?"＝「そして今日、どのクラスが一番つまらなかった？」
"Was the teacher nice to you?"＝「先生はあなたに優しかった？」
"Were you able to have a good time with your friends?"＝「友達と楽しい時間を過ごせた？」
ご参考までに。
What was your most interesting class at school today?
What was your favourite/best class at school today?
「今日学校で一番楽しかったクラスは何？」は、次のように聞くことができますよ。
ーWhat was your most interesting class at school today?
one's most interesting class で「一番面白かったクラス」
ーWhat was your favourite/best class at school today?
one's favourite/best class で「一番好きな/よかったクラス」
ーWhich class was the most boring today?
「今日一番つまらなかったクラスは何？」
What was ...? で始める代わりに、Which class was ....? という聞き方もできます。
ーWas your teacher nice?
「先生優しかった？」
nice で「優しい」
ーDid you get along well with your friends?
「友達と仲良くできた？」
to get along well with one's friends で「友達と仲良くする」
ご参考まで！
アメリカ合衆国 
カナダ 
