My boy knows quite a few words. Mostly nouns though, and really no sentences or phrases yet. (Unless you count phrases like "all done" which qualify as one word to the baby vocabulary researchers, because it's a single idea.)
But he knows the word "help" and uses it frequently. Primarily it's because a toy isn't behaving as he believes it should and he wants help making it work (the train that connects magnetically comes to mind).
In fact, the first string of ideas I heard him connect was "Nu-no! Hehp!" asking his biggest sister for help with his toys. I love that he sees her as someone that can solve his problems. (His other sister can be quite helpful too when she chooses.)
About a month ago he learned to say both his sisters names. He calls out for them frequently when they're not at the house. And he's always willing to go in the car, especially to go get one of them.