Grammar is important, dude!
Luke: [age 8, doing homework] "What do I put here: is it a comma or an apostrophe?"
Me: [looks over] "That would be an apostrophe."
Luke: "The flying comma!"
Me: "Yes. I'm glad you are asking about punctuation like that."
Luke: "I gotta tell you: grammar is important, dude!"

Luke, age 7, inexplicably left this little folded note for my wife.

If you can’t read it, the interior says, “I am a long time in the bathroom”. 

Sorry, kid, that isn’t news.

Compound words
[Scene: Luke, age 7, is doing homework involving compound words]
Me: "All right. You've filled in all these words from the clues. Now you have to write a list of compound words that you think of by yourself. Can you think of some?"
Luke: "Fartblossom!"
Me: "Hmm. I think that is technically two words."
Luke: "Okay, how about: buttcheeks!"
Me: "That might be two words, but I don't know. I've seen it as one word before."
Luke: "Should I write it down?"
Me: "Sure."
Luke: "Seriously? I don't think my teacher would find that appropriate."
Me: "You're probably right."
Luke: "I don't think Mom would find it appropriate, either."
Me: "You're probably right about that, too."
Luke: "I should just stick to words that are appropriate. Like 'snowshoes'."
Me: "Right again."
Luke: "You know, Dad, you're not being very helpful."
Zing-Zang
Luke: [age 7, holding a piece of paper] "Look at this."
Me: "What is it?"
Luke: "That's how you spell my name."
Me: "Hmm. It looks like a bunch of squiggles."
Luke: "It's in my new language, Zing-Zang. Nobody else knows it."
Me: "If nobody else knows Zing-Zang, how do you know you're spelling it correctly?"
Luke: [shrugs] "I just make it up as I go."
Strawberry Story

[The following story was dictated by Beth, age 3, to her grandmother]

Strawberry sees a lion, and the lion says, “ROAR!”

Strawberry says, “Get out of my way, Lion!”

The lion doesn’t listen to Strawberry.

So Strawberry walks away to her home, and the lion walks away to his home in the woods.

The next day, Strawberry tells her brother about the lion.

They decide to just leave the lion alone.

The End

I'm a poet
Luke: [age 6] "You know, I'm a poet who does sinful things. I can make any word rhyme with 'butt'."