YOU SAID:

Let's run really fast, until my legs don't work

INTO JAPANESE

足が動かなくなるまで、本当に速く走ろう

BACK INTO ENGLISH

Let's run really fast until your legs stop moving

INTO JAPANESE

足が動かなくなるまで本当に速く走ろう

BACK INTO ENGLISH

Let's run really fast until our legs stop moving

INTO JAPANESE

足が動かなくなるまで本当に速く走ろう

BACK INTO ENGLISH

Let's run really fast until our legs stop moving