Styrofoam: It's used for doggie bags at restaurants, as your bowl at the corner ice cream store, and so forth. I hate to think of the landfill it ends up in.
Handcarts: We see lots of manual laborers hauling building materials or other supplies through the streets on handcarts outfitted with automobile tires. It must be cheaper than the alternatives, but it feels out of place in a mostly modern city.
Dogs: The Argentines love dogs and they own a lot of them. Not just small ones, either: I feel that the average dog here is larger than the average dog in the US. There are dog parks dotted throughout the city. Professional dog-walkers are a common sight as well. We haven't seen the legendary (mythical?) ones with 30 dogs, but 6-8 is a typical number and 10 is not unusual. The dogs are generally well-behaved.
Water: Every morning, most sidewalks are washed down with a hose. I was amazed at the waste of water, until I realized that we are no longer in dry Madrid or dry Patagonia: Río de la Plata is over a mile wide. And without the water, it would be hard to wash off the dog poop that covers the city sidewalks -- a depressing similarity to Madrid. Most pet owners are responsible, but clearly there are plenty who are not.
On the topic of water, you can get rained upon at any moment -- not because of the clouds, but because of air conditioning units that are constantly dripping on the sidewalk.
The bus is cheap: I can ride it three times for a dollar. That is, if I can find a bus stop. The online route maps match the printed book that describes the routes, but neither of those matches where the bus actually goes. The first day I tried to go to the university, I waited over half an hour at a clearly-marked bus stop on the official route, but no buses arrived. That happened again when the route changed without warning. My new approach is to walk through the neighborhood until I happen to spy the bus I want, then walk along its path looking for a bus stop. Usually these are marked by a sticker pasted to an electrical pole, but the stop nearest my office is unmarked. Once I find a stop, each day I look down the street to see how the bus gets to that stop, and I backtrack the bus a little bit more to find a better stop. I would gladly pay more -- even upwards of 40¢ per ride! -- in order to have reliable route information.
Buses are everywhere. Each line has its own three-color paint scheme so you can tell which bus is which from far away. This makes them not quite as concerned with putting the route number on the buses, though. I was surprised that buses switch to a night schedule, with very few on the streets, by 11:30; the metro also stops running. This was unexpected for a city with a reputation for staying up late.
Safety: Unfortunately, I have to take the bus to work even though I would prefer to walk the less than 30 minutes. Multiple people have warned me about the danger of bridges over a railroad track and of the university area in general. Despite all the talk about crime, I feel comfortable in the city now, and certainly in our upscale neighborhood. I would probably be fine walking, but it's not worth the risk, especially since there is no computer for me in my office and so I have to carry my laptop to work each day. I might buy a bicycle.
At night, every business locks heavy shutters or metal grilles over its windows. We went a long time not knowing what some stores were, since their signs were covered over. Businesses don't do a good job of indicating their address and especially their opening hours on their storefronts or websites; you are just supposed to know, or maybe to phone since the phone numbers are often given prominently.
Gender segregation: This has been most noticeable in school, but then again that has been our main interaction with Porteños (residents of Buenos Aires). All the kindergarteners wear the same uniform, but starting in first grade the girls wear skirts and the boys wear shorts. The students in each grade line up at assembly in two rows -- one for boys and one for girls. There were a fair number of fathers at the information session on the day before school started, and some dads dropped their kids off on the first day of school and even got emotional. But since then it has been mostly moms, and the few dads who come talk among themselves. I was struck by that in Madrid, too: on the one day all year that parents were permitted in the school (a potluck breakfast), every father but me sat together at a table on the side of the room and talked among themselves, and the mothers and children circulated around the room.
Schoolwork: We were warned off the public schools, so we chose a private school. The school day is long -- 8am to 4:30pm -- because they teach the government-mandated curriculum in the morning and an English one in the afternoon. It's not as academically rigorous as in the US; for example, learning to read by the end of kindergarten is explicitly not a goal. On the other hand, naturally kindergarteners are writing in cursive and first-graders are using a fountain pen.
Openness: We have found the school very forthcoming and open about what is going on with the children, and each kid has a communication book that goes home with information every day. There are limits to all things: the school still wants parents to trust them and leave the school to educate the children as it sees fit. An even bigger contrast has been the friendliness of the parents. There were a few in Madrid with whom we became friends and who helped us to feel welcome, and we loved that there were a number of birthday parties early in the year to help us meet the other parents. But here the parents have been effusively welcoming, from inviting Cat to the unofficial kindergarten mothers' breakfast to giving us tips about doctors and renting apartments. We even got added to the class mailing list! It may not be a completely fair comparison, since we chose a public school in Madrid and a private school in Argentina. At work, I have also felt right at home, perhaps because the department has people who see ways to productively interact with me.
Kissing: Everyone in Argentina kisses. Women greet women by kissing. Women greet men by kissing. Men greet men by kissing. (This weirds out the homophobes.) People greet strangers by kissing. Naturally I kiss with my host at the University of Buenos Aires on arrival and departure. Every once in a while I forget myself and put out my hand for a handshake when I am introduced to someone new, but then I realize just how rude that is and I kiss instead. The kissing is really more of an air kiss. You press your right cheek against the right cheek of the other person, then both of you make a kissing noise into the air. But some people actually do plant a real kiss on the cheekbone, ear, or neck of the other person. I have not yet advanced to that stage.
Class: We live in a nice part of Seattle, but here our neighborhood is upscale.
* There are lots of apartment buildings with fancy marble foyers, and designer shops are less than 10 minutes away. I'm not used to this. But some people are, and a few people at school have even told us that we don't live in the right part of the neighborhood, though not precisely in so many words. It's true that our area isn't as nice as the heart of Belgrano and that the neighborhood gets noticeably less posh just 1 block from us to the northeast and 3 blocks to the northwest. Our current apartment is on a big street and we are certainly looking forward to changing that. Mostly, though, we want to shorten our morning walk to school and to have appliances that work.
* Many apartments, including the one we are in, include a maid's apartment with its own small bathroom. Naturally there is a portero (receptionist) for each building, and since many older buildings like ours are very narrow, there can be 10 porteros in 100 meters, which seems a waste. Our apartment, building, and neighborhood in Madrid were not particularly fancy, but it too had a maid's room and the building had a portero (for 3 times as many apartments).
* Our landlady doesn't know how to cook and was surprised that we expected pots, pans, bowls, and the like in our furnished apartment. She confidently told us, "There is no recycling here -- it's Buenos Aires, after all", when there are recycling bins on many streets, including multiple ones a block from our building.
* Most schools we interviewed at accepted our kids after interviewing us to determine our jobs, background, etc. We chose a school that interviewed the children as well.
Waiting in line: Long queues are a fact of life here. Argentina seems to have an unspoken policy of hiring a smaller number of customer-facing staff than other countries. This perhaps reduces prices, but customers have to pay in their time. For instance, you should not expect quick service even in a pricey restaurant and even if the waitstaff is working hard, because there just aren't very many staff compared to the number of customers. As another example, I waited over an hour in a major bank to pay a bill (a transaction that took approximately two minutes). There were 50 people waiting in line when I arrived. We also see long lines snaking out of lottery stores (which also serve as bill-payment centers), and I'm not sure whether that is because they are paying bills, buying lottery tickets, or something else.
Some aspects of life in Buenos Aires are no surprise, such as needing to do your shopping at lots of little stores rather than a few big supermarkets or general retailers. The fruits and vegetables are great.
I have found that some stereotypes do not reflect reality. For instance, I see no evidence that Porteños are particularly stylish or concerned about their appearance. I haven't been in nightclubs, but anyway the generalization does not hold. We also haven't had any problem finding vegetarian food in restaurants or stores, even though the country does love its barbecues.
The Spanish here is different than that of Spain, but not nearly as different as we had been warned. We quickly got used to the differences in pronunciation (the animal llama is pronounced "yama" in Spain but "shama" here) and grammar (voseo is the most prominent example). For vocabulary differences, we just ask what the word means and we have learned to use "choclo" instead of "maiz" for corn, "mani" instead of "cacahuete" for peanut, etc. Argentines understand the standard words, even if they claim that their word is also standard and not a regional variant. My colleagues at UBA tell me that I speak with a decided Iberian accent due to the way I roll my Rs and where I place the accent in certain words, and I've had people in shops ask if I am from France, though most people recognize that my native language is English.