YOU SAID:

I will slit your neck

INTO JAPANESE

私はあなたの首を切り裂きます

BACK INTO ENGLISH

i will cut your neck

INTO JAPANESE

私はあなたの首を切ります

BACK INTO ENGLISH

i will cut off your head

INTO JAPANESE

私はあなたの頭を切り落とします

BACK INTO ENGLISH

i will cut off your head