Learn Polish: Jak się dzisiaj masz?

In Polish, asking about someone's well-being doesn't use the verb 'to be'. Instead, you use mieć (to have) along with the word się (oneself). So, Jak się masz? literally translates to 'How do you have yourself?'

What is the role of the word jak at the start of the sentence?

Jak means 'how'. Just like in English, you place this question word at the very beginning of the sentence to ask for details, rather than asking a basic yes/no question with Czy.

Why is się placed before dzisiaj and masz?

The word się is a bit picky about where it sits. It prefers to be the second word in a sentence and tries to avoid being the very first or very last word. Tucking it right after the first word (Jak) sounds the most natural in Polish.

Can I use this phrase to greet anyone?

No, this is an informal greeting. Because it uses masz (the casual 'you' form), you should only use it with friends, family, or people your own age. You would not use this with a boss or a stranger.