YOU SAID:

I really need to do this once

INTO JAPANESE

私は本当に一度これを行う必要があります。

BACK INTO ENGLISH

I really need to do this.

INTO JAPANESE

私は本当にこれを行う必要があります。

BACK INTO ENGLISH

I really have to do this.

INTO JAPANESE

私は実際にこれを行う必要。

BACK INTO ENGLISH

I really have to do this.