YOU SAID:

they didn't get enough sleep last night, not because they were playing video games but because they had been assigned too many assignments

INTO JAPANESE

昨夜、十分な睡眠がとれなかったのは、ビデオゲームをしていたからではなく、割り当てられた課題が多すぎたためだった

BACK INTO ENGLISH

I didn't get enough sleep last night because I had too many assignments, not because I was playing video games.

INTO JAPANESE

昨夜は十分な睡眠がとれませんでした。それは、ビデオ ゲームをしていたからではなく、課題が多すぎたからです。

BACK INTO ENGLISH

I didn't get enough sleep last night. Not because I was playing video games, but because I had too many assignments.

INTO JAPANESE

昨夜は十分な睡眠が取れませんでした。ビデオゲームをしていたからではなく、宿題が多すぎたからです。

BACK INTO ENGLISH

I didn't get enough sleep last night. Not because I was playing video games, but because I had too much homework.

INTO JAPANESE

昨夜は十分な睡眠が取れませんでした。ビデオゲームをしていたからではなく、宿題が多すぎたからです。

BACK INTO ENGLISH

I didn't get enough sleep last night. Not because I was playing video games, but because I had too much homework.