彼はそう言ったとたんに後悔した。

彼はそう言ったとたんに後悔した。

No sooner had he said it than he was sorry.

彼(かれ)はそう言(い)ったとたんに後悔(こうかい)した。

Kare wa sō itta totanni kōkaishita.

彼 (かれ)

he; him; his; boyfriend

は (は)

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

そう (そう)

so; really; seeming; appearing that; seeming that; looking like; having the appearance of

言う (いう、ゆう)

to say; to utter; to declare; to name; to call; to go (e.g. "the alarm went ping"); to make a noise

途端に (とたんに)

just as; in the act of; as soon as; at the moment that

後悔 (こうかい)

regret; repentance; remorse

Readings: ヒ、かれ、かの、か.の

Meanings: he, that, the

Readings: ゲン、ゴン、い.う、こと

Meanings: say, word

Readings: ゴ、コウ、のち、うし.ろ、うしろ、あと、おく.れる

Meanings: behind, back, later

Readings: カイ、く.いる、く.やむ、くや.しい

Meanings: repent, regret