Explain why as you observe the night sky over time stars appear to move westward across the sky

Well there is a couple of reason 1. The way you looking eye's turn

2. The Earth is always moving so it might move the stars The Milky way moves like the earth.

And 3. It's stars A Trillion Gazillion Star's so Yeah!

Hope you found your answer : D If not ill continue science class and edit! : D