YOU SAID:

I will smack you upside the head with this water bottle.

INTO JAPANESE

この水筒であなたの頭を殴ってあげるわ。

BACK INTO ENGLISH

I'm going to hit you over the head with this water bottle.

INTO JAPANESE

この水のボトルであなたの頭を殴ってやるよ。

BACK INTO ENGLISH

I'm going to hit you over the head with this water bottle.