What drives you crazy the most about Korean?

[manyakumi]

That having been said, maybe this is a silly Q, but when you're combining verbs, how do you know how many times to you have add -시? For example, 가시고 싶으세요? vs 가고 싶으세요? Or ~하시려고 하셨어요 vs 하려고 하셨어요... I've seen both, and I'm not sure what the real difference is... is the former that much more polite, or a bit over the top?

You don't need to add 시 on every single verbs but just on last one.
As you mentioned,
가시고 싶으세요 and 하시려고 하셨어요...
These kinds of sentences are grammatically wrong but still happen everywhere in colloquial situations. Maybe because they were not sure when they should end their sentence.

I notice people tend to mix their politeness levels up a bit at times...
For example, when my cousin talks to my mom, he might use 반말 when the subject is first or third person, but use 존뎃말 when the subject is "you" - i.e. 나도 가야 돼? 고모 호자 가세요. I notice this on TV too...

If you got friendly with one who is older than you, it becomes possible to have a conversation like that unless you forget some important rules to talk.

Never say 반말 to them on...
1. Addressing or calling them
2. Saying imperatives
3. End of a question
4. Saying "먹다(to eat)" and "자다(to sleep)" verbs.

I think it's kinda rude to say "나도 가야 돼? 고모 혼자 가세요." when I'm having no contexts for that.
Maybe because 고모 is not much older than the speaker, or there was another person who would be OK if the speaker speaks 반말 to. (the speaker's mom for example)
It would be nicer to say as "나도 가야 되나? 고모 혼자 가세요."
In this case, the first sentence could be considered as a self-talking, not an asking.

[kyuree]

Of course there are a lot of things that I struggle with while learning Korean but since my own mother tongue has a quite difficult grammar and I had to learn French in school (haha), I'm very greatful that Korean doesn't have a lot of difficulties other languages have, e.g.

- the verbs don't change with gender or number
- the adjectives don't change w/ number, there is no gender for words (German has three genders: male, female and neutral)
- there are no grammatical cases (German has four, Russian has more)
- the plural is always regular and can often be ommitted
- the script is very easy and you can get by quite well without seriously studying Hanja (in comparison to Japanese where you need it)
- Korean doesn't have tones like Chinese, Thai or Vietnamese
- there's no subjunctive mood as in Romance languages
- the pronounciation is clear from the spelling (it is not in English!!! basically in English you have to know the word in order to pronounce it correctly or you can guess... sometimes wrong)
- ...

can't think of anything any more haha...

well, I would never want to learn a language like German if it wasn't my mother tongue... German grammar is a bitch haha. There are few foreigners who have mastered it completely even after years of living here unless they're scholars or something... You can be fluent but normally you will get the grammar slightly wrong, there are just too many difficulties (mostly word gender, cases, many foreigners struggle with syntax)

[cheri]

You don't need to add 시 on every single verbs but just on last one.
As you mentioned,
가시고 싶으세요 and 하시려고 하셨어요...
These kinds of sentences are grammatically wrong but still happen everywhere in colloquial situations.

Thank you for clearing that up! That's very helpful.

- the verbs don't change with gender or number

When I was learning French for the first time in school, I kept questioning, "Why? Why? Why?" Haha. I suppose all the nuances are what makes languages so fascinating. ^^ I've never attempted learning German... but it sounds tough!