[OPINION] - does language really matter if they all do the same thing?

[Python Baby]

Are programming languages like spoken languages, in the sense
that they all say the same things, just using different words?

Like many PHP people, I was never a "real" programmer, but just
picked up PHP as my HTML websites started to mature.  Now that
even my PHP sites have grown, (50,000 lines of PHP!), I got
interested in object-oriented approach.  Since my old website
needed an overhaul anyway, I thought it'd be a good time to learn.

I start learning Ruby.  Then Python.  Wondering if, since I'm 
about to re-write my entire website anyway, if I should use
Ruby or Python instead of PHP.

As I've fretted over this for way too many hours, I started wondering:

Can Ruby do something (important) that Python can't?
Can Python do something (important) that PHP can't?
Can PHP do something (important) that Ruby or Python can't?

Are they all just the same, and it's just a matter of taste?

Should I stick with PHP for the same reason that pop singers
worldwide sing in English for maximum compatibility with the medium?

Though PHP wasn't design for OOP should I use it that way anyway?

Any opinions on the subject, from people that know and use many
languages, would be appreciated.