YOU SAID:

fell down stairs with pencil

INTO JAPANESE

鉛筆で階段から落ちた

BACK INTO ENGLISH

I fell down the stairs with a pencil

INTO JAPANESE

鉛筆で階段を下りました

BACK INTO ENGLISH

I went down the stairs with a pencil

INTO JAPANESE

鉛筆で階段を下りた

BACK INTO ENGLISH

I went down the stairs with a pencil