寝返り(negaeri: turning over while sleeping in bed; betrayal)
to sleep + to return
The following two sentences are nearly identical but convey very different ideas:
1. 彼は一晩中寝返りを打った。
Kare wa hitobanjū negaeri o utta.
The boy tossed about all night.
[Sense 1: Turning over while sleeping in bed]2. 彼は寝返りを打った。
Kare wa negaeri o utta.
He went over to the other side.
[Sense 2: Betrayal]A breakdown of the kanji:
彼 (kare: he)
一晩中 (hitobanjū: throughout the night)
one + night + suffix meaning
“throughout”
打 (u(tsu): to attack, to strike, to impress upon)It’s unclear which definition of 打 applies here. Maybe with restless sleep, one keeps striking the mattress.