Learning Korean 4: The Summer of Chapter 4

I have been stalled on Chapter 4 of my textbook, 한국말 하시는군요 (Book 3, Intermediate Korean 1) for at least two months now. It covers a great deal of territory, and a lot of the material is crucial, but some of the topics feel more like ornamentation than nuts-and-bolts Korean. It's been a slog. And the summer in Seattle has been really hot. I just haven't been so motivated. Anyway.

1. The so-called sentential modifiers: -은, -는, 을

These endings are the workhorses of Korean, as they allow for relative clauses and a whole suite of much more complex sentences. For instance, 먹은 과자 ("the snacks I ate"), 먹는 과자 ("the snacks I eat), and 먹을 과자 ("the snacks to eat"). Things get more complicated than this, though. For one thing, the past tense endings -던 and -ㅆ던, as in 먹던 and 먹었던. Actually, I still don't understand those last two or know how or where to use them. (I think they express the past progressive or pluperfect or... something.) So I'm sticking to the basics for now. I just know that these modifiers are very common and are used in a lot of constructions.

2. The "all you need to do is" construction: -으면 되다

Literally, this is "if you (verb), it works," but in practice, it means "you only need to (verb)." 비가 오면 우산을 가지고 가면 돼요. ("If it rans, you just need to take an umbrella.")

3. It takes (money, time, etc.) to...: -는 데 걸리다 / 들다

주차 자리를 찾는 데 얼마나 걸려?! ("How long does it take to find a parking space?!")
영화를 보는 데 십 불 들어요. ("It costs ten dollars to see a movie.")

4. Have ever done: -은 적이 있다

미국에서 여행한 적이 있어요? ("Have you ever traveled in the US?")
전 어렸을때 스키를 탄 적이 없었어요. ("When I was young, I never went skiing.")

Then there's the slightly (but totally) different form that uses 어/아 본 적이 있다 and means "have tried doing." No, I don't understand which situations call for which of these, as the English translations, while different, seem very similar and, in some cases, close enough in meaning to make understanding the distinction difficult.

5: Know (or not know) how to: -을 줄 알다 / 모르다

운전할 줄 알아요? ("Do you know how to drive?")

Note these two constructions that are similar (to this English-speaker's brain) but not very similar (according to Korean-speaking brains):

운전하는 방법을 알아요? ("Do you know how to drive?" That is, "Do you know the method of driving?")
운전할 수 있어요? ("Can you drive?" That is, "Are you able to drive?")

6: The "noun about a noun" construction: N1에 대한 N2

그 건물에서 일하는 사람에 대한 비밀이 있어요. ("I have a secret (N2) about a person (N1) who works in that building.") See the relative clause? 그 건물에서 일하는 사람 ("a person who works in that building")! Excitement!

7: Through, via, making use of: N-을 통해(서)

그 영화를 통해서 한국말을 배웠어요. ("I learned Korean from (watching) that movie.") That is not actually true about me and any movie. Also, the -을 통해서 construction is usually (often? widely?) used with people. As in "I learned through the squat stranger that the train was canceled." So maybe my example about the movie isn't the most apt.

Update (8/31/15): I'm calling it. Moving on to chapter 5. Enough, already.