YOU SAID:

the dog was transforming into the street when it saw a fox.

INTO JAPANESE

犬はキツネを見たとき、通りに変身していました。

BACK INTO ENGLISH

The dog was transformed into a street when it saw a fox.

INTO JAPANESE

犬はキツネを見て通りに変身した。

BACK INTO ENGLISH

The dog turned into a street when it saw a fox.

INTO JAPANESE

犬はキツネを見て通りに変わった。

BACK INTO ENGLISH

The dog turned into a street when it saw a fox.