I could do a lot better in some cases...

no

I stand up for others all the time, but I've never been able to stand up for myself.

Most of the time, I always try to stand up for myself.

I stand up for myself but I'm always unsuccessful but I think it's because I am young.

Sadly

I try to, but I don't always.

It took me years to be confident enough to do it. Sadly, with having to move, I lost a lot of that confidence

Well, I stand up to my annoying older brother, but I'm not very good at it.

I'm pretty passive in general, but every once in a while I've been getting the courage to stand up for myself.

I'm with MacytheStrange. I stand up for others, but not myself.

I wish I could, but I never had the courage to do so...

I always do but people always say I overreact.

I don't often need to, but I'm more likely to let other people walk all over me.

On Fanpop I definitely do, but not so much in real life. I need to work on it, I can be a bit of a pushover sometimes.

^What Mongoose09 said.

mostly to my friends and family

I am way too touchy and vindictive to not do this.