YOU SAID:
i pay at the cash register
INTO JAPANESE
私はレジで支払います
BACK INTO ENGLISH
I will pay at the cashier
INTO JAPANESE
私はレジ係で支払います
BACK INTO ENGLISH
I will pay with cashier
INTO JAPANESE
レジで支払います
BACK INTO ENGLISH
I will pay at the cash register
INTO JAPANESE
レジで支払います
BACK INTO ENGLISH
I will pay at the cash register
That didn't even make that much sense in English.