coordinates of phase space

lakmus

Hi,
I am u little confused about general coordinates at all. I don't know
functions of what are they.
For exhample on Hamiltons phase space there are [itex]p[/itex] and
[itex]q[/itex]. Are thesse function of time?
I've seen that [itex]\frac{\partial q }{\partial t}=0[/itex] but total derivation
is not . .. what is difference if [itex]q[/itex] is function jus [itex]t[/itex]?

Thanks a lot!.