YOU SAID:
I saw a fat guy fall down stairs.
INTO JAPANESE
私は太った男が階段から落ちるのを見た。
BACK INTO ENGLISH
I saw a fat man fall down the stairs.
INTO JAPANESE
私は太った男が階段から落ちるのを見た。
BACK INTO ENGLISH
I saw a fat man fall down the stairs.
That didn't even make that much sense in English.