YOU SAID:

I just fell up the stairs

INTO JAPANESE

ちょうど階段を上がったところだった。

BACK INTO ENGLISH

I was just going up the stairs.

INTO JAPANESE

階段を上るところだった

BACK INTO ENGLISH

I was going up the stairs.

INTO JAPANESE

私は階段を上がるところだった。

BACK INTO ENGLISH

I was about to climb the stairs.

INTO JAPANESE

私は階段を昇ろうとしていた。

BACK INTO ENGLISH

I was about to climb the stairs.