YOU SAID:

their pet monkey flung himself at the wall and broke his arm

INTO JAPANESE

彼らのペットの猿は壁に身を投げ、彼の腕を折った

BACK INTO ENGLISH

Their pet monkey threw himself into the wall and broke his arm

INTO JAPANESE

彼らのペットの猿は壁に身を投げ、彼の腕を折った

BACK INTO ENGLISH

Their pet monkey threw himself into the wall and broke his arm