Why can I not reply to comments on my pictures?

Hi, I'm rather new to this website so I'm still learning how to use it. I had a comment off someone and it said that she had ...

I dont know why comments are disabled in my picture somebody knows how can I change that any answer is welcome thank you.

im talking to people on here and some random pictures keep being put onto our comments and were like what the ? is it somet...

Like what myspace does because it would be so much more convenient instead of having to look through all your pictures to che...

Well I was wondering why can we have a reply thingy on our comments it would make everything much easier!its kinda annoying t...

like, if its a how to on how to do something, why do people tell u how to do it in the comment?

Do you know if there a way to know when someone has commented your picture? (Besides the friend update thing at the side) Or ...

How do I get people to comment my pictures?

How do you upload pictures on to the website?

Whenever I click on a picture, ITS HUGE!! how can I change this?