YOU SAID:
The man slowly walked down the hallway, laughing to himself about the small yellow dog.
INTO JAPANESE
男はゆっくりと廊下を歩き、小さな黄色い犬のことを笑った。
BACK INTO ENGLISH
The man slowly walked down the hallway and laughed at the little yellow dog.
INTO JAPANESE
男はゆっくりと廊下を歩いて、小さな黄色い犬を笑った。
BACK INTO ENGLISH
The man slowly walked down the hallway and laughed at the little yellow dog.
That didn't even make that much sense in English.