My little brother is now 7 years old. He practically idolizes me. It's adorable most of the time, just not when I'm busy and he needs something from me. I like teaching him random phrases in Hawaiian and Klingon. For example, when I leave for work or school, I'll say "A hui ho" (until we meet again), and he'll run to the door, and give me a hug and say "a huwea ho". It's cute.
On the downside, he picks up some things he shouldn't. For those of you familiar with the auiocassete Conversational Klingon, you know that it starts off by introducing you to some Klingon curses... Well, I was listeing to it one day and he just happend to be able to hear it from the other room. He spent the next week cursing in Klingon. People kept asking me what he said; I kept silent.
A few useful things that he has learned to comprehend when I shout them out are:
gho'be jay'! (umm... very no...)
a hui ho (mention above)
Aloha (if you don't know...)
nuq DaneH? (what do you want?)
chu'! (engage!--I say it in my car a lot...)
and a few more...