きっとsurely, undoubtedly, almost certainly, most likely (e.g. 90 percent), sternly, severely, having no slack, rigid, stiff, tight, suddenly, abruptly, instantly

受験(じゅけん)にはきっと合格(ごうかく)するだろう。

You will surely pass the exam, right?

明日(あした)はきっと晴(は)れる。

It is sure to be clear tomorrow.

彼(かれ)ならきっと生(い)きて帰(かえ)ってきます。

If it's him, he is sure to return alive.

天気(てんき)予報(よほう)士(し)：「来月(らいげつ)頃(ごろ)にはきっと雪(ゆき)が降(ふ)り始(はじ)めるでしょう。」

Weatherperson: 'It is probably sure to start snowing around next month.'

独(ひと)り言(ごと)：「こんな悪(わる)い事(こと)が起(お)きるなんて…きっと夢(ゆめ)に違(ちが)いない！！」

Monologue: 'To think that such a bad thing as this would happen... There is no mistaking that it's surely a dream.'