Formal:
* Andrzej (pronounced "AHN-dʒey") is the most common and formal way to say Andrew in Polish.
Informal:
* Andrzejek (pronounced "AHN-dʒey-ek") is a more informal and affectionate diminutive form of Andrzej.
* Andrzej can also be used informally, but it's usually used with someone you know well.
Other options:
* Andrej (pronounced "AHN-drey") is a less common but also acceptable spelling.
* Andrzej can also be shortened to Antek (pronounced "AHN-tek"), especially for children.
So, the best way to say "Andrew" in Polish depends on the situation and your relationship with the person you are addressing.