Or “Stop bothering me.” That’s how I used it when I was that age.
I like this one too. I really think annoying him about it by gentle teasing is the way to go.
You could also try:
Uncle Q: cool fact
Nephew: “I know…”
Uncle Q: “Know what?”
Nephew: “Y’know… that stuff you just said…”
Uncle Q: “What did I say that you already know?”
Nephew: repeats what you said
Uncle Q: “Yeah, I know” in same tone of voice
Some of these Dopers need to lighten up a little about the behaviour. Teasing will sort it without giving him some huge smack down over a non-issue.
Teasing is a form of bullying, dontcha know? 
Please don’t reply by stating “I know.” Thank You.
I did not know that.
My 8-year old stepson does this. “I know” seems to be shorthand for “I am not listening to a word that you’re saying”.
Here’s an actual example from the other weekend when we went for a hike.
Valgard: “Careful running on that bridge, it’s muddy and slippery and I don’t want you to fall.”
Stepson: “I know!”
Slip, fall, wham.
Stepson: (Cries and grabs bruised shin)
Valgard: (After making sure there is no massive loss of blood, protruding bone, etc) “OK, do you see why I asked you to be careful?”
Stepson: “Yes”
Valgard: “Why?” (await suitable explanation so that I know this was in fact a learning moment, even though the half-life of such knowledge is about 10 minutes)
I love how so many of these suggestions involve operant conditioning.
This is exactly what I’ve been thinking as I read the thread. It may be presumptuous and pompous for an uncle/aunt to try to educate a kid on proper manners, but everyone has the right to set out the boundaries of their interactions with others. If you feel someone is giving a rude, dismissive response, what’s wrong with saying, “When you respond like that, I feel like you’re being rude and dismissive.”
As you wish.
At a wild guess, this is more of an emotional response, probably meaning something like “OK then” not a literal statement of fact, so I’d suggest just telling him what you want him to do, and only resorting to sarcasm if he doesn’t respond to that. If you’re constantly sarcastic about it but he doesn’t understand why he shouldn’t say that, he may get the message “uncle is sarcastic” not “uncle wants me to stop saying that”.
(Presumably it’s more important not what he says, but whether he actually imbibes the conversation, but that may be a step further :))
I’m not seeing the disrespect, to be honest.
When my 10yr old friend says it, I get the feeling she’s disappointed to be micromanaged. It’s a way for her to say, “I do not need direction any more, I am growing up!”
Yes, even when she does need direction. So I began prefacing my remarks with, “I’m aware you likely already know this, but I feel compelled to mention…” At least the response was slightly delayed and filled out to, “I actually did know that!”
Well, that’s it then.
All that R&D on a surgically implanted high voltage capacitor device that charges from zero to full from static electricity & discharges during very specific vocal commands just shot right to Hell…
I even had a catchy name for it: Mother’s Little Helper…
Regarding that line in The Empire Strikes Back, people laugh at it, but director Irvin Kershner has explained it pretty well. They had to do many takes with opportunities for improvisation, Harrison Ford was weary, and out it came. Kershner liked it because it works; saying “I love you too” puts one at a disadvantage of sorts, rather than solemnly and/or happily acknowledging said love.
It always made sense to me.
And yes, please don’t let him say “like” constantly.
If people keep saying “I know” to what I’m saying, I’m either repeating things or saying things unnecessarily. I pull back and ask the questions. If they renege or fail on an “I know” issue, I demand payback: “I thought you knew this?” “I would think two reminders would have been enough.”
Way to go the_diego. Demand that payback from a ten-year-old! Harass the little bugger! Pit your wits against him!
Quartz, do you talk with your nephew about things he’s curious about, or stuff you think he should be interested in, or things that are very interesting to you?
Absolutely.
It doesn’t matter. By ten years old, a child should be learning that their family members are not clowns and dancing monkeys to be considered as long as they are entertaining and dismissed when they grow dull. There are polite, socially acceptable ways to redirect a conversation that you are not particularly interested in, and teaching these things is exactly what adults are for.
That said, it does depend on how close the uncle is. My uncle was very close, and more like a big brother. I’d see him every day and he was definitely in charge of teaching me manners. A more distant uncle might be differen.
Well, if by “it works” you mean “it makes the female members of the audience want to flay your so-called hero” then yes indeed it does.
