What's the difference between "Czy Jesteś mężczyzną?", and "Jesteś mężczyzną?"
No difference, in meaning. Czy makes seeing that it is a question clear co written forms of comunication use it almost exclusively, Czy is a bit informal. You can put stress on "czy" when it is important, you can use czy question when your intonation is less likely to be heard. I'd advice any new learner of Polish to use "czy"
By saying "when it's important", you mean, for example, if I found something and I ask a person: "But is it yours?", and not just "Is it yours?"?
I do not understand you. :( I do not know a difference between examples you have provided.
"Czy" also translates to if in relative speech, so if you men something like:
I asked IF this is yours .
The first example was when you're mad i.e, and you ask someone "IS, IT, YOURS?". The second one was just normal asking.
This curious "czy" is the same particle used in Esperanto for questions: "ĉu" /tʃu/ (Zamenhof was polish). Another language using that kind of yes-no question particle would be chinese with 吗 (ma), or thai and its ไหม (mai).
It depends on what you mean. It has declension like feminine nouns. But adjectives and pronouns describing "man" are always masuline or masculine-personal and verbs always take masculine/ masculine-personal forms.
This is helpful to know. I was previously confused by this, but now I think I understand.
But it means "man", "male" is sometimes acceptable if it means more or less the same thing in English.
The explanation for "Czy" says interrogative. What if I'm really just don't know if the person I'm talking to is a woman or a man? How would I ask him/her?
"czy" just makes it clear that you are asking a yes/no question. It has nothing to do with whether you're talking to a man or a woman.
In Present Tense, the verb doesn't show the gender of the subject of the sentence. It does in Past Tense and it can show it in Future Tense, though.
In Present Tense, the adjective would show the gender of the subject. So for "Are you tall?" you can ask "[Czy/] [ty/] jesteś wysoki?" if you are asking a man, and "[Czy/] [ty/] jesteś wysoka?" if you are asking a woman.