YOU SAID:

add watermelon to the pot and let boil

INTO JAPANESE

鍋にスイカを入れて沸騰させます

BACK INTO ENGLISH

Put watermelon in a pot and bring to a boil

INTO JAPANESE

鍋にスイカを入れて沸騰させる

BACK INTO ENGLISH

Put watermelon in a pot and bring to a boil