Alex is our narrator for most of the story. The letters to Jonathan and the chapters that sound as though they're written in another language and filtered through Google Translate are written by him. He lives in Ukraine with his Father, Mother, and younger brother, whom he calls Little Igor. His father works for a travel agency called Heritage Touring and is also a giant abusive jerk who hits Alex on more than one occasion.
Even though Jonathan Safran Foer (who is also a character in the book) has his name on the cover, we think this is really Alex's story. He's the one who changes over the course of the book, and he's the one who ends up, shall we say, illuminated by the journey to find Jonathan's grandfather's hometown.
Sorry Jonathan, you'll just have to create a tragic story for your grandfather out of thin air. (Or maybe you can borrow Alex's. We won't tell.)
Alex is super cocky at first, telling us in the very first paragraph of the book: "I have many many girls" (1.1) and talks about a variety of what we're assuming are sex positions, like "the Inebriated Kangaroo, the Gorky Tickle, and the Unyielding Zookeeper" (1.2). What is this, The Kama Sutra is Illuminated? Alex also has a very high opinion of himself, describing his great hair, "aristocratic smile" (1.8), and a stomach that is fat yet strong. (Like Homer Simpson's). Actually, in the first few pages of the book, he reminds us a lot of Borat: clueless, arrogant, and hilarious.
But don't let Alex fool you. He's not really the illiterate buffoon he seems to be. In fact, it turns out that he's actually pretty savvy: admit it, you totally bought into his inflated self-presentation, didn't you? But as the book progresses, this self-created image is stripped away to make room for the real Alex, who turns out to be a little nicer and a lot smarter than he presents himself. In his first letter to Jonathan, he admits writing "the non-truth about how I am tall. I thought it might appear superior if I was tall" (4.8). In other words, he thinks people will like him more if he's tall. Later on, he even admits "I have never been carnal with a girl"(17.7).
Say it isn't so!
So, what's the deal with Alex? Why can't he just be his short, virginal self? (Hey, at least he can drive.)
Culture. As a Ukrainian, he's expected to be masculine in all the typical masculine ways: money, girls, and fat but strong bellies. He also misunderstands other cultures. For example, he says early on "I had the opinion that Jewish people were having shit between their brains" (1.5). (Don't worry, this opinion changes too as he gets to know Jonathan better.)
We have a hard time blaming the guy, though, because his dad is a real jerk. We're not sure why he turned out that way, but we know that Grandfather blames himself—and tells Alex, "A father is always responsible for how his son is" (29.84).
Alex takes this line to heart. He sees himself as a father figure to his little brother, and he wants a good life for him. He saves up money to get them to America, and when he realizes that's not going to happen, he does the next best thing: boots his dad out of the house. Although children might inherit his ancestor's mistakes, Alex knows that he's not responsible for dealing with their destruction in the present.
Once Alex loses the lothario pose, we see his soft side. He loves his clumsy little brother, and sometimes goes off on little asides to him, like this classic:
Look at me, Little Igor, the bruises go away, and so does how you hate, and so does the feeling that everything you receive in life is something you have earned. (10.25)
These messages are the equivalent of "It Gets Better" except regarding abusive parents instead of sexuality-related bullying. It's a shame he has to say them in writing instead of in person, but it's not just Ukraine: sensitivity and masculinity seem to be mutually exclusive in most cultures.
Through the travel agency, Alex meets Jonathan Safran Foer, a writer who is searching for the town his grandfather grew up in. Alex is the same age as Jonathan, whom he often calls "the hero of this story" (1.2). They become BFFs and bond over writing, with Alex taking much of Jonathan's editing suggestions and Jonathan… well, Jonathan doesn't seem to take any of Alex's suggestions.
In fact, we never get to see Jonathan's correspondence to Alex, so we never really know if Jonathan values Alex's friendship or merely takes it for granted. It could be cultural differences and physical distance that make Jonathan appear distant. Alex acknowledges this, saying, "We became like friends while you were in Ukraine, yes? In a different world, we could have been real friends" (4.13).
Or it could be that Jonathan considers Alex a subject for his book and not a friend at all. In fact, Jonathan takes a dispassionate view of Alex, writing about him more as a character than as a friend. Alex is clever enough to notice that attitude when he reads Jonathan's diary: "At first it made me angry, but then it made me sad, and then it made me so grateful, and then it made me angry again, and I went through these feelings hundreds of times, stopping on each for only a moment and then moving to the next" (18.35).
Despite all this emotional confusion, Alex does care a lot about Jonathan. He writes to him: "You are the only person who has understood even a whisper of me, and I will tell you that I am the only person who has understood even a whisper of you"(25.50), which is super bro-mantic and possibly the sweetest sentiment in the whole book.
So why will they never write to one another again? We're not sure, but we suspect that, for writer-Jonathan, character-Alex has served his purpose.