Past Simple vs. Past Continuous

Past Simple

vs.

Past Continuous

Let's make a sentence with these phrases: 1. I walk / down the Old Market Square in Poznań 2. I see / Brad Pitt

WHEN

WHILE

I was walking down the Old Market Square in Poznań WHEN I saw Brad Pitt.

WHILE I was walking down the Old Market Square in Poznań, I saw Brad Pitt.