Bucky Barnes: [Webbed down after the Falcon got rid of Spider-Man.] You couldn't have done that earlier?
Sam Wilson: [Also webbed down.] I hate you.
Bucky Barnes: Can you move your seat up?
Sam Wilson: No. (01:25:00)
Iron Man: OK, anybody on our side hiding any shocking, or fantastic abilities they'd like to disclose, I'm open to suggestion.
Natasha: Looking over your shoulder should be second nature.
Falcon: Anyone ever tell you you're a little paranoid?
Natasha: Not to my face. Why, did you hear something?
Sam Wilson: I don't know how many fights you've been in, but there's not usually this much talking.
FedEx Driver: Are you 'Tony Stank'?
Tony Stark: So, you're the Spiderling. Crime-fighting Spider. You're Spider-Boy?
Peter Parker: S-Spider-Man.
Tony Stark: Not in that onesie, you're not.
Peter Parker: It's not a onesie. (01:19:00)
Tony Stark: If we don't do this, it will be done to us.
Clint Barton: As much as I hate to admit it, if we're going to win this fight, some of us might have to lose it.
Spider-Man: [of Captain America's shield] That thing doesn't obey the laws of physics at all.
Clint Barton: I retire for 5 minutes and it all goes to shit.
Sam Wilson: I just want to be sure you've considered all our options. Because people who shoot at you usually wind up shooting at me too.
Spider-Man: Hey guys, you ever see that really old movie, Empire Strikes Back?
James Rhodes: Jesus Tony, how old is this guy?
Tony Stark: I don't know, I didn't carbon date him. He's on the young side.
Scott Lang: Hank Pym did say to never trust a Stark!
Tony Stark: Who are you?
Scott Lang: Come on, man.
T'Challa: Two people in a room can get more done than a hundred.
King T'Chaka: Unless you need to move a piano.
T'Challa: In my culture, death is not the end. It's more of a stepping off point. You reach out with both hands and Bast and Sekhmet, they lead you into the green veld where... you can run forever.
Natasha Romanoff: That sounds very peaceful.
T'Challa: My father thought so. I am not my father.
Natasha Romanoff: T'Challa, Task Force will decide who brings in Barnes.
T'Challa: Don't bother, Ms. Romanoff. I'll kill him myself.
Sam Wilson: So you like cats?
Steve Rogers: Sam...
Sam Wilson: What? Dude shows up dressed like a cat and you don't wanna know more?
Steve Rogers: Your suit. It's vibranium?
T'Challa: The Black Panther has been the protector of Wakanda for generations. A mantle passed from warrior to warrior. And now because your friend murdered my father, I also wear the mantle of king. So I ask you, as both warrior and king, how long do you think you can keep your friend safe from me? (00:55:00)
Chosen answer: We never get a specific explanation to what happens to him when he enlarges. Hank Pym explains to him that when he shrinks, it's the result of reducing the distance between atoms which is why he retains his original mass. However, being a giant with a mass and strength of only 160lbs would not be very advantageous in a fight, so they must have found a way for him to grow in size and strength in this situation. Ultimately, we just don't know - the movies and comics differ in a great many respects, so there's just not enough information to work with. Might technically qualify as a mistake, but it's something which could easy be solved with an in-universe answer, however scientifically dubious.