How do you stop the "I CAN'T!" in a 3 year old?

With my 4 year old son it was colors, reading, finding something.  Everything became "I can't".  The way he said it was so down on himself.  Finally I said "Yes the hell you can.  You can do this and whatever else you choose to and if I hear that again I will put soap in your mouth".  I didn't actually need the soap but he stopped saying it and started DOING instead of saying "I can't".  I don't recommend this, just saying my experience.  With my 3 year old I tell her "yes you can now do it".  That works for her. 

Don 't give in. Tell her that since she wants to act like a baby, you're going to start treating her like one, ( ie putting her to bed earlier, no tv, whatever it is that "big girls" do)

WELL DO YOU DO IT FOR HER WHEN SHE SAYS THAT? IF YOU DO I WOULD STOP. SHE WILL OUT GROW THIS AS THEY ALL DO SHE WANTS YOU TO DO IT FOR HER,IT MIGHT MAKE HER FEEL IMPORTANT IF SHE FEELS SHE IS BEONG IGNORED, IM NOT SAYING YOU ARE IGNORING HER BUT SHE DOES IT TO GET YOUR GOAT. DONT LET IT BOTHER YOU. SHOW HER SHE CAN DO IT HERSELD BUT SHOWING HER HOW YOU PUT ON YOUR JACKET!!!! SEE MOMMY IS A BIG GIRL AND SHE CAN DO IT??? BUG GIRLS DRESS THEMSELVES THEN GIVE HER A BIG GIRL TREAT GOOD LUCK

My three year old doesn't say I can't but "I want Mommy do it" about everything from putting on clothes to picking up a toy to play with or wanting me to hand him things he drops etc. I try to remember it's hard to be a big boy sometimes and am patient about it. It doesn't mean I do it for him every time or that I don't encourage him to do it on his own but I don't let it bother me or act irritated about it.

I'm just wondering, was there a recent family seperation, death, something, to provoke the child's extra security needs? Cuase I'm seeing it not as a "I can't" but as a "help me do I want you here" thing, simply based on your responses. I'm not judging just trying to guess, becuase say there was a security issue, I'd LET the child regress for awhile and slowly coach them back into confidence. Intolerance will only hurt that fragile self esteem worse. On, the other hand, if its simply the ADD problem,try this: do what my mom did for me. Say, "Ok dont then" and walk away. Unless its a medical emergency, stopping the plans and letting them miss out on thingswon't kill you. I may even encourage an, "oh, crap, if I cant do it, and nobody else will, it wont happen :( I've got to!" response. (at least it did for me as a child)