“This is so metaphorical.”
The son of the poor Kim family repeats this phrase a few times throughout the film to the point it becomes a running gag. He says it whenever something is working out in his family's favor, so he is always using it just slightly incorrectly. However, the film is full of metaphors and symbols, and his line unwittingly acknowledges this.
“They are nice because they are rich.”
While they are eating and drinking in the Parks' living room, Ki-taek observes that Mrs. Park is very nice, even though she does not need to be. His wife corrects him, suggesting that the reason Mrs. Park is nice is because she is rich. Having money affords Mrs. Park a kind of social grace that poorer people do not have. Niceness, in her mind, is a privilege, to a certain extent.
“You know what kind of plan never fails? No plan. No plan at all. You know why? Because life cannot be planned.”
After their apartment gets flooded, Ki-taek and his children go to a gymnasium to spend the night. Ki-woo asks his father what his plan is, but Ki-taek, beaten down by his difficult experiences, feels defeated and suggests that, for people like them, it is best not to have a plan, since life is often unexpected.
“If there’s one thing I hate, it’s people who cross the line.”
Mr. Park tells his wife that he hates it when someone "crosses the line," which for him means someone who is socially inferior to him acting as if they are not socially inferior, as if they are his equal. This line, which he says in relation to his first driver, shows the ways that Mr. Park harbors certain prejudices against members of the lower classes.
"Jessica, only child, Illinois, Chicago. Classmate Kim Jin-mo, he's your cousin."
This is a little song that Ki-jung makes up in order to remember her fake identity before entering the Parks' house for her interview.
"Rich people are naive. No resentments. No creases on them."
While they eat in the Parks' living room, Ki-taek comments on the naivety of rich people, the fact that their wealth makes them somewhat out-of-touch with reality and alienates them from the actual stakes of the world.
"What is it? Like an old radish. No. You know when you boil a rag? It smells like that."
While Ki-taek and his kids hide under the coffee table, Mr. and Mrs. Park lie on the couch, and Mr. Park describes the unsavory way that Ki-taek smells. It shows just how insensitive Mr. Park is to the people who work for him, his inherent condescension.
"Look at this. Your pulse is racing. The heart doesn't lie. An exam is like slashing through a jungle. Lose that momentum and you're finished. The answer to #24? I don't care. Slashing through the exam, dominating it! That's all I care about. What you need is vigor."
During his interview for the tutoring job, Ki-woo tutors Da-hye while Mrs. Park watches. With this line, he gets very aggressive and forthright with his pupil, grasping her wrist and suggesting that she must take her test with vigor. It is an erotically charged moment, in which he is speaking somewhat suggestively, and Mrs. Park loves it.
"Honey, that woman Chung-sook... Oh god. What a nice person. She kicked me down the stairs."
After the struggle between the Kim family and Moon-gwang and her husband, Chung-sook kicks Moon-gwang down the stairs to the bunker, to prevent the Parks from seeing her. Moon-gwang suffers a concussion and goes to her husband, muttering this line.
"I forgot something in the basement under the kitchen."
This is the line that sets off the string of events that lead up to the climactic moments of violence. While the Kims are enjoying a meal in the Parks' house, Moon-gwang arrives unexpectedly, insisting that she has to check on something in the basement. We have no idea what she is referring to, but the arrival seems to promise something unsavory and shocking.
