Πριν φύγεις, κοίτα αν το κουμπί στο παλτό σου είναι καλά ραμμένο.

to be

Breakdown of Πριν φύγεις, κοίτα αν το κουμπί στο παλτό σου είναι καλά ραμμένο.

• καλά: well
• σου: your
• πριν: before

Questions & Answers about Πριν φύγεις, κοίτα αν το κουμπί στο παλτό σου είναι καλά ραμμένο.

What does κοίτα mean here? Is it literally look or more like check?

It is the 2nd person singular imperative of κοιτάω / κοιτώ.

Literally, κοίτα means look, but in this sentence it is more natural to translate it as check:

• κοίτα αν... = check whether / see if...

So here it means something like:

• Before you leave, check whether...

It is addressed to one person informally.
If you were speaking to more than one person, or using formal you, you would normally say κοιτάξτε.

Why is it φύγεις after πριν? Why not φεύγεις?

Because after πριν meaning before, Greek commonly uses the aorist subjunctive-type form for a single action viewed as complete.

So:

• πριν φύγεις = before you leave

Here φύγεις comes from φεύγω (to leave / go away), but it is not the ordinary present form.

Why not φεύγεις?

• φεύγεις = you are leaving / you leave
• φύγεις = the form Greek uses here for before you leave

The idea is not ongoing action, but the event of leaving as one whole action.

Is φύγεις a past tense form?