YOU SAID:
I saw a reindeer run across a road
INTO JAPANESE
トナカイが道路を横切って走っているのを見ました
BACK INTO ENGLISH
I saw a reindeer running across the road
INTO JAPANESE
トナカイが道を横切って走っているのを見ました
BACK INTO ENGLISH
I saw a reindeer running across the road
That didn't even make that much sense in English.