Baba is an important part of The Kite Runner's storyline and his influence on Amir makes up the dynamic of Amir's mentality. Baba's distant fathering approach to Amir resulted in Amir craving his attention and manifests itself throughout the novel e.g. when Amir pretends he doesn't see Hassan being raped in the alley.
Fortunately for you, Baba's actual presence in the play is relatively small, which means that there aren't that many quotes to remember about him and that it's fairly easy to pick up the way in which he speaks (since there isn't that much variance).
Baba shows bravery throughout the novel, from risking his life to speak out against the Russian soldier who wanted to rape a woman being smuggled in the truck, to refusing cancer treatment.
Stern, Non-yielding Opinions
Baba's controversial opinions and morals do not falter throughout the novel. Examples of this include aggressively demanding for a new doctor after having found out that his one had Russian origin, and not supporting Amir's wanted career path (writing) because he thought that it wasn't prestigious enough.
Extroverted - "a people person"
As well as many stories of Baba's past lively social life being told and Amir directly saying that Baba always had friends and family around him, many instances of this are seen in the storyline. Baba even throws parties when he is in Pakistan, as he is trying to escape from the Taliban, fearing his death. In America, he throws parties with other Afghani's who had fled from danger too.
Relations to Other Characters
When speaking to Amir
Baba's speech varies slightly when speaking to Amir depending on where he is in the story, with it's affection towards him modulating between little and mild.
Little - when Amir embarrasses Baba in public (such at the party in Kabul where Amir had poorly addressed Assef and other guests) and when Amir throws up during car journeys.
Mild- the only times where Baba shows a great deal of positive emotion towards Amir is after he graduates from American college, when Amir gets married, and after Amir wins the Kite tournament.
Great swings of negative emotion are seen when Amir asks Baba if he ever thought about getting new servants wherein Baba says "you bring me shame" and says that if he ever repeats what he said, he would beat him.
Most of the time, Baba does not use many words when speaking to Amir. Here is an excerpt from the novel where Amir receives his birthday presents:
"you like it [new bike]? Baba said, leaning in the doorway to my room. I gave him a sheepish grin and a quick "Thank you." I wish I could have mustered more.
"We could go for a ride," Baba said. An invitation, but only a half-hearted one.
"Maybe later. I'm a little tired." I said.
"Sure," Baba said.
"Thanks for the fireworks," I said. A thank you, but only a halfhearted one."
"Get some rest," Baba said. walking towards his room."
The repetition of "half hearted" emphasises the forced father-son relationship that Baba and Amir have, going through the motions of what should be done as it were, between a loving father and son.
Excerpts from the Text
Disappointment in Amir
"As he was slipping the key into the lobby door, I said, “I wish you’d give the chemo a chance, Baba." Baba pocketed the keys, pulled me out of the rain and under the building’s striped awning. He kneaded me on the chest with the hand holding the cigarette. “Bas! I’ve made my decision.” “What about me, Baba? What am I supposed to do?” I said, my eyes welling up.A look of disgust swept across his rain-soaked face. It was the same look he’d given me when, as a kid, I’d fall, scrape me knees, and cry. It was the crying that brought it on then, the crying that brought it on now. “You’re twenty-two years old, Amir! A grown man! You…” he opened his mouth, closed it, opened it again, reconsidered. Above us, rain drummed on the canvas awning. “What’s going to happen to you, you say? All those years, that’s what I was trying to teach you, how to never have to ask that question.” (p156 – 157)"
“It hurts to say that. But better to get hurt by the truth than comforted with a lie.” - Baba (p58)
That was when Baba stood up. It was my turn to clamp a hand on his thigh, but Baba pried it loose, snatched his leg away. When he stood, he eclipsed the moonlight. “I want you to ask this man something,” Baba said. He said it to Karim, but looked directly at the Russian officer. “Ask him where his shame is.”
They spoke. “He says this is war. There is no shame in war.”
“Tell him he’s wrong. War doesn't negate decency. It demands it, even more than in times of peace.” (p115)