YOU SAID:

I walked downtown and bought a slice of pizza

INTO JAPANESE

私は繁華街を歩いてピザを一切れ買った

BACK INTO ENGLISH

I walked downtown and bought a piece of pizza

INTO JAPANESE

私はダウンタウンを歩いてピザを買った

BACK INTO ENGLISH

I walked downtown and bought a pizza

INTO JAPANESE

私は繁華街を歩いてピザを買いました

BACK INTO ENGLISH

I walked downtown and bought a pizza