くたくたに

completely exhausted; until completely soft

→ くたくた
phrase Rare #34,433
completely exhausted; until completely soft Used adverbially to describe being utterly worn out, or cooking something until it becomes very soft. In everyday speech, it is especially common in くたくたに疲れる, meaning “to be completely exhausted.”
JA: 仕事の後、くたくたに疲れて何もしたくなかった。
EN: After work, I was completely exhausted and didn't want to do anything.

くたくたに疲れた

I'm completely exhausted.

くたくたに疲れました

I'm completely exhausted.

昨夜帰ってきた時はくたくたに疲れてたんだ

I was completely exhausted when I got home last night.

くたくたに疲れていたので彼女はすぐにぐっすり眠ってしまった

She was exhausted, so she quickly fell into a deep sleep.