Why can't you say "Ti lide jsou velke"? What type of form is "velci"?
Velcí is required for masculine animate.
what makes it a masculine sentence?
Lidé is plural of člověk. Masculine.
Ti osoby jsou velci - not accepted?
ty osoby jsou velké - osoba is feminine
Ti lidé jsou velcí! - This is specifically for a group of men, correct?
Nope. Grammar gender does not equate real-world' gender. Lidé is masculine animate, that's why you use velcí.
Would "Ty osoby jsou velke" be correct as well?
It is accepted.
Do we judge a plural gender based on it's ending or based on the gender of it's singular?
Well, both, to some extent. The main is the singular gender, but there can be a modification that makes an inanimate noun animate. E.g., den -> dny (inanimate), but dni (animate) or even very poetic and bookish dnové (animate).
i made a mistake so correct me i use ( i ) as in velci. to people i dont know
and ( s") as in proc" nejis" to people i do know or children???
I have no idea what you are telling us. Please do not use so many question marks!!! It may look rude exactly like those three exclamation marks I just used.
I don't quite understand what you're asking about either. If you'll try again, maybe we can help.
Hello, again I don't understand why "To" is not accepted
"To" is not used / translated in this sentence because the demonstrative pronoun "to" is separated from the noun as an independent subject.
Ti ludé = Those people
To jsou ludé = Those are people
I changed the position of jsou and velci - wrong.
:( me too
See my answer to hmitev.
Couldn't i say in that order: "Ti jsou velcí lidé" ?
That would mean "Those are big people."