YOU SAID:
a donkey stole my mothers mug of cold coffee
INTO JAPANESE
ロバが母の冷たいコーヒーのマグカップを盗んだ
BACK INTO ENGLISH
The donkey stole my mom's cold coffee mug
INTO JAPANESE
ロバが母の冷たいコーヒーマグを盗んだ
BACK INTO ENGLISH
The donkey stole my mom's cold coffee mug
That didn't even make that much sense in English.