YOU SAID:

when i was at the park i saw an ice cream truck

INTO JAPANESE

公園にいたときにアイスクリームトラックを見ました

BACK INTO ENGLISH

I saw an ice cream truck when I was in the park

INTO JAPANESE

公園にいるときにアイスクリームトラックを見ました

BACK INTO ENGLISH

I saw an ice cream truck when I was in the park