寝転がされていた

[zuotengdazuo]

あれからすぐに気を失ってしまった士道が目を覚ますと、またも<フラクシナス>の医務室に寝転がされていた。

Hi. As far as I know 寝転がる is 五段動詞 so its passive form should be 寝転がられる. But in this sentence, it is 寝転がされる. I wonder why? Besides, why is passive form used here? He was lain down?

Thank you.

 

[Toritoribe]

That's "寝 + the passive form of 転がす". 寝 would be the -masu stem of 寝る, which is used to make a compound verb (e.g. 食べ残す, 飲み終わる, はじけ飛ぶ, etc.). This is also the etymology of 寝転がる.

 

[zuotengdazuo]

Thank you. I failed to think of it as a compound verb.