newbie :-) question on reflow pdf and epub

Hi all,

sorry for a (maybe) simple question.

I got my Sony PRM T1 a few days ago and copied my free pdf files onto it.
I was confused that I could not change the font size.

I read a few threads in this forum and learned: there are text pdfs that reflow (well) and text pdfs that do not reflow

I used Calibre to create epubs from those pdfs and unfortunately they also do not reflow.

Question from a "newbe":
- can I see somewhere in an pdf file if this is "well" reflowing or not?
- can I change the pdf to a well reflowing pdf, e.g. "reflow tag"
- can I create a well reflowing epub from a text pdf that does not well reflow, e.g. via calibre

Thanks for some guidance.
Cheers,
bj.