Hi everyone, I have study materials from 2020 and recently heard that the syllabus was updated in 2024. How significant are the changes? Would it still be possible to prepare and pass using the older materials, or do I need to get the updated ones?

First of all, this is a genuine question. I am not trying to start any argument.

English is my second language. My native language is Slavic and I am from Central Europe. I mostly learned English on my own through watching videos and reading, not through school English classes.

Recently, I was in the United States on a student exchange and attended classes at a local high school. During that time, I noticed a few situations that surprised me. One student asked what “poultry” meant during a science class. Another did not know the word “rodent.” Someone else mentioned that the SAT has difficult vocabulary such as “acquire.” These were not underperforming students. All of them got into great colleges, took multiple AP classes, and are set to graduate with high GPAs.

I always thought of these as fairly basic words, so it surprised me. I know them in both English and my native language, so I never considered that they might be unfamiliar to native English speakers.

I will be coming to the United States for college soon, and it made me think about a couple of things.

1. I want to make friends and communicate naturally. I do not want to sound like I am trying too hard or like a smartass. Are these kinds of words something native speakers sometimes struggle with? Should I simplify my vocabulary in conversation or in essays? I have also heard that using more advanced words in assignments can make writing seem like it was generated by AI. Is that something I should be careful about?
2. If these words are generally considered basic, is there a reason some students might not know them? Is it differences in education, reading habits, or something else?

I am just trying to understand how people actually communicate and what language they use for everyday conversations. Any insight would be greatly appreciated.