Questions & Answers about Kto mówi o nowym projekcie?
Kto means who and is the normal question word for asking about the subject of the sentence.
In Kto mówi o nowym projekcie?, kto is the person doing the action, so it is in the nominative role, just like who in English.
Compare:
- Kto mówi? = Who is speaking?
- Kogo widzisz? = Who do you see?
Here kogo is different because it is an object, not a subject.
Mówi is the 3rd person singular present-tense form of mówić (to speak / to talk / to say, depending on context).
So:
- ja mówię = I speak / I am speaking
- ty mówisz = you speak
- on/ona/ono mówi = he/she/it speaks
With kto, Polish normally uses 3rd person singular, so:
- Kto mówi? = Who is speaking?