Leonard: What?
Amy: Sheldon has something he'd like to say.
Sheldon: I'm sorry I didn't react appropriately. You and Penny are bringing new life into the world. Congratulations. I can't wait to meet it.
Leonard: "It"?
Sheldon: That's a gender-neutral pronoun. If you're offended, take it up with the English language.

Amy: Sheldon.
Sheldon: What? Did you finish? Great job.

Sheldon: Can you sing Soft Kitty?
Penny: What?
Sheldon: My mom used to sing it to me when I was sick.
Penny: I'm sorry, honey, I don't know it.
Sheldon: I'll teach you. [sings] "Soft kitty, warm kitty, little ball of fur, happy kitty, sleepy kitty, purr purr purr." Now you.
Penny: [sighs] [sings] Soft kitty, warm kitty…
Sheldon: Little ball of fur. Keep rubbing.
Penny: Little ball of fur.

Sheldon: Sing Soft Kitty.
Penny: That's only for when you're sick.
Sheldon: Homesick is a type of being sick.
Penny: Come on. Do I really have to?
Sheldon: I suppose we can stay up and talk.
Penny: [sings] Soft kitty, warm kitty, little ball of fur. Happy kitty, um…
Sheldon: Sleepy kitty.
Penny: Sleepy ki…
Sheldon: No. Start over.
Penny: [sings] Soft kitty, warm kitty, little ball of fur. Happy kitty, sleepy kitty, purr, purr, purr.

Sheldon: [through virtual presence device] Sing me Soft Kitty.
Penny: Really, you want me to sing Soft Kitty to a computer monitor?
Sheldon: Would you rather come over and sing it to me in person?
Penny: [sings] Soft kitty, warm kitty, little ball of fur.
Sheldon: Closer to the microphone.
Penny: Happy kitty, sleepy…
Sheldon: No. You have to start over.
Penny: [sings] Soft kitty, warm kitty, little ball of fur. Happy kitty, sleepy kitty, purr, purr, purr.

Sheldon: Does this mean you're not going to sing Soft Kitty?
Mary: No, I will always sing you Soft Kitty. [sings] Soft kitty, warm kitty, little ball of fur…
Leonard: [opens door] Mrs. Cooper, were we supposed to take that pie out of the oven?
Sheldon: Get out!
Mary: Well, that was rude.
Sheldon: Well, I know, but he means well. Sing.
Mary: [sings] Happy kitty, sleepy kitty…
Sheldon: What are you trying to pull, Mom? From the top.
Mary: [to God] This is what I'm talking about. [sings] Soft kitty, warm kitty, little ball of fur…

Sheldon: Did you bring the dehydrated low-sodium soy sauce?
Leonard: Check.
Sheldon: Freeze-dried spicy mustard?
Leonard: Check.
Sheldon: Flash-frozen brown rice, not white?
Leonard: Uh, oh, sorry.
Sheldon: Not to worry. I hid it. Bazinga!

Sheldon: [through virtual presence device] This is a photograph of the 1911 Solvay Conference on the theory of radiation and quanta. Using Photoshop, I've introduced a few anachronisms. See if you can spot all 24. I'll give you the first one. Madame Curie should not be wearing a digital watch. And go.
Leonard: That’s it. Bye-bye. [turns off screen]
Sheldon: [screen turns on] Bazinga.
Leonard: Whoa! [car swerves]
Sheldon: I have an override switch.
Leonard: I almost died!
Sheldon: And I'm safe and sound in bed. Who's crazy now?
Leonard: I'm still going to go with you.

Sheldon: No, no. You save your apologies for after you've had disappointing coitus with Penny.

Sheldon: Come on, Leonard, if you roll a six, Penny dies horribly in a nuclear meltdown. See what I mean when I say the fun is real?

Sheldon: I'm not interested in being published in Mad Magazine. Zingers fly fast in the Thunderdome, Barry.

Sheldon: Sheldon Cooper does not do cozy.

Sheldon: There was obvious someone else in her apartment. I have no choice but to assume the worst, given Leonard's lengthy sea voyage and Penny's famously ravenous nether regions.

Sheldon: You know, Amy, I don't understand. Are we broken up or not? It's like you can't make up your mind.
Amy: It's because you're not giving me any space to think.
Sheldon: Well, you should think fast. Because men can sire offspring their entire life, but those eggs you're toting around have a sell-by date.

Amy: You know, I had a feeling you were using the wrong computational model, but I didn't say anything 'cause you're so sensitive.
Sheldon: Just because I'm easily bothered by light, heat, smell, sound, and the way birds look at me does not mean I'm sensitive.