YOU SAID:

A quick and swift black monkey stole my banana whilst i ate it under the willow tree

INTO JAPANESE

柳の木の下でバナナを食べている間、素早く素早く黒い猿が私のバナナを盗んだ

BACK INTO ENGLISH

A black monkey stole my banana quickly and quickly while eating a banana under a willow tree

INTO JAPANESE

柳の木の下でバナナを食べている間、黒い猿が私のバナナを素早く素早く盗んだ

BACK INTO ENGLISH

A black monkey stole my banana quickly and quickly while eating a banana under a willow tree