I think 'slice' is a better word for it, actually.
A slice of bread is called "kromka chleba" in Polish.
Yes, definitely. Theoretically, it could mean "I cut" in some uneven pieces that don't make any sense, but more probably I slice, so I get pretty slices for sandwiches. Whether "I cut" in English implies cutting it the way to prepare sandwiches anyway, that I don't know.
If someone asked me to cut bread, I would assume they wanted it sliced. Though usually with food, you specify slice, cube, chop, dice, etc, and if you do use "cut", it's either already understood how you want it done, or else you'll just be asked "how do you want this cut?"
Of course, sometimes you just say what the food is being cut for and assume intelligence on the part of the person you're talking to. If I said "Can you cut bread for sandwiches, please" I hope the other person would be able to figure out that I want it sliced.
The pronunciation of this sentence sounds like je kroję chleb instead of ja kroję chleb
"przestać" is to stop doing something... that's a rather surprising question.
Ok, but if i tell my wife... "Krojesz mięso, proszę!" and she knows, that i want to eat Goulash that could be not translated in "Please slice the meat! (?) So i think "kroić" should be "cut in anyway you like" and to slice is a special way and should be another word!?
I'm afraid that "krojesz" is not a word...
"kroisz" is 2nd person singular, but that's just a Present Tense declarative form, so it's "You are cutting meat".
"krój" is technically the imperative 2nd person form, but as it's imperfective, that doesn't make much sense in this example.
"pokrój" (perfective, ergo: cut it 'succesfully' and finish it) is the right form in your sentence :)
Well... I'd say that "kroić" is simply "to cut in a way that makes most sense in the given situation".