YOU SAID:
why do we know do how to
INTO JAPANESE
なぜどうすればいいのか。
BACK INTO ENGLISH
Why should I do it?
INTO JAPANESE
なぜ私はそれを行う必要がありますか?
BACK INTO ENGLISH
Why should I do that?
INTO JAPANESE
何故連れて行くんだ?
BACK INTO ENGLISH
Why should I do that?
That didn't even make that much sense in English.