YOU SAID:

the black dude was going to the store

INTO JAPANESE

黒人の男は店に行っていた

BACK INTO ENGLISH

the man in black was going to the store

INTO JAPANESE

黒服の男は店に行っていた

BACK INTO ENGLISH

The man in black went to the store

INTO JAPANESE

黒服の男は店に行きました

BACK INTO ENGLISH

The man in black went to the store