It is currently recognized that dolphins are very intelligent.
一般にイルカはとても頭がいいとされている
It is very irresponsible of him not to answer my letter.
ぼくの手紙に返事をくれないとは彼はまったくいいかげんだ
It serves [Serve(s)] you right.
((略式))ざまあみろ，いい気味だ
It was absolutely [really] excellent.
((略式))すごくいい，実にすばらしい
It would be better still not to produce it.
それを生産しないことの方がいっそういいと思う
It'd be a good idea to have some rest.
少し休むのがいいと思うよ
It's a date.
その日時［時間］でいいよ，それで決まりだね（◆会う約束の日時の都合を確認して）“How about Friday [tomorrow night]?” “It's a date.”「金曜日［明日...
It's all good.
((米略式))（状況などが）とてもいい，大丈夫
It's better that he (should) be present.
彼がその場にいるほうがいい
It's fine [a fine day], isn't it?
いい天気ですね
