It's unacceptable (for anyone) to commit an act of violence.
(だれも)暴力をふるうことは許されない
It's up to her to decide what to do next.
次に何をやるべきか決めるのは彼女しだいだ
It's very [highly] competitive to ask her out.
彼女をデートに誘うのはすごい競争だ
It's very hard to get that across to some people.
相手によってはそれをうまく伝えるのは非常に困難だ
It's very sweet of you.
どうもご親切に
It's vital to take action now to prevent this disease.
この病気の予防に今対処することが不可欠だ
It's warm enough to eat outdoors today.
今日は野外で食事できるぐらい暖かい
It's way too real for me.
それは私にはあまりにリアルすぎる
It's well funny.
ものすごくおもしろい
It's worth a go.
それはやってみる価値がある