Can't you also modify the predicate and also modify verbs using adverbs

Wait nvm that's the next lesson, oopsies

Why is Question 1 an argument? What am I being persuaded of? It seems to me like the writer is merely stating a decision they have already made and then describing their circumstances further in the last sentence.

The videos outline three ways to identify an argument

1. Trust your gut and discern the main point of what the passage is saying and whether that's encapsulated in a statement.

2. Look at each claim and see if the other claims in the passage support it.

3. Look for indicator words.

I think #1 is good if you have good logical instincts. #2 takes longer but works if you do not have good logical instincts or want to make sure you do not mess up. #3 only works situationally but it is the fastest.

I recommend you use method #2 and to trust yourself more. Do not second guess, the LSAT is not like math, looking at the words and questioning yourself will really only waste the time you have for each section and probably lead you down the wrong path that goes against your gut.

You're right that by rephrasing and rearranging the premises you could turn the first sentence into an argument. But that indicator word is precisely why the first sentence is not a conclusion, because the other sentences are not introduced to support it.

Also, the 1st premise is not a conclusion, in my opinion, because it is not supported by the other sentences in the passage. At best, the 1st premise, if it were a conclusion, would be significantly weaker (more assumptions) than the actual argument made.

Looking at your reframed argument, p1 and p2 do not support the conclusion (train service suffers when combined) very well. P1 and P2, whether true or not, do not increase the likelihood of the conclusion being true.

Railroads can either combine (1st premise), divide (2nd premise), or focus on one element of the industry (conclusion). The 1st premise is meant to support that the third option, focusing on one element of the railroad industry, is the best by ruling out the option of combining the railroad.

"Train service suffers when a railroad combines" is not a conclusion because it is not supported by any of the other sentences in the passages. It stands by itself and we know conclusions cannot do that (as they need premises), thus that sentence is not a conclusion.

A premise is more accurate because it has reasonable assumptions. Yes, both are true.

For example: The tiger example's premises are more accurate than the trash bin one because it has more reasonable assumptions like that tigers are mammals. The trash bin example makes assumptions such as "Mr. Fat Cat would want to eat the salmon" that are less reasonable, hence the premises are less accurate and more vulnerable to criticism.

What you're doing here is inferring an extra premise that is not in the passage. Linguists have conducted comparative analyses, that is ALL you know, you cannot add the part where you say "communication exists in various regions and eras." Those are your OWN words and NOT in the passage. Without inferring more and adding premises on our own the statement about what linguists have conducted do not support the claim that language is a universal phenomenon, hence it's not an argument.

Ok, let's say "being in new york" is A and "being in the USA" is B. You need B in order to even think about A (you cannot think about being in New York if you aren't even in the US). Thus, A needs B in order to even be true, hence B is necessary for A. B is not sufficient for A because B by itself does not guarantee A (being in the USA does not guarantee you are in New York, as you rightfully pointed out). Since B does not automatically lead to A, it is not sufficient.