What do the endings 다는 and 거야 translate to in a sentence such as
그 모든게 오해였다는 걸 너도 알거야 and
참 우습게 들린다는 말도.
Ok, I'm going to give you my meager understanding of this pattern (grammatically accurate explanation not guaranteed):
'는' is typically a subject indicator but also indicative of a continuing action or condition, there are numerous patterns where '는' becomes a conjunctive between sentence clauses. In your examples 는 is preceded by the a plain style declarative clause terminated in 다 --this is not divided as "다는."
'거야' here '거' comes from '것' meaning 'thing,' but sometimes can refer to a situation or condition as well, and '야' is the informal, intimate (and can be rude), declarative exclamation 'it is.' I believe the full polite form of this would be '것입니다,' other forms you will encounter '겁니가' '거예요' '거다' ='thing it is'
(그 모든게 오해였다) +는 걸(것을) (너도) (알)(거야)
(All those things were misunderstood)+that (thing을 *objectifies the entire preceding clause) (you also) (will know) (thing it is)
*That all those things were misunderstood is something you will also realize.
*You'll see that you/he/she/they misunderstood everything!
참 우습게 들린다는 말도. *not quite a complete sentence but we all know sentence fragments are common in everyday conversation
(참 우습게 들린다)+는 (말)(도) *말이다.
(Truly humorous to hear)+that (words/saying) (also are)
*Those words are also laughable to hear.
*Don't make me laugh. *What a joke.
I hope that helped you but I wonder if you are more confused now than before.
In this pattern ~ㄹ/을 거예요 'something will be.' In this case 거예요 거야 is used as a supposition about things present as well as indicating the future when preceded by verbs having 'ㄹ' added to them. Some examples 알(know), 할(do), 살(buy), 먹을(eat) 거야
알 거야 - lit. will be known I/he/you will know
할 거야 - (I) will do it.
살 거야 - (I) will buy it.
먹을 거야 - (I) will eat I/we am/are gonna eat.
Supposition form: Michael이 알 거야, 걔한테 물어보자. - Michael will know, let's ask him. We suppose that Michael knows (now).
I've never heard anyone say '알다' to indicate 'knowing' in the present tense, instead '안다' is used "너도 안다" means 'you also know' 너도 아는 거야 -You also know this(it's obvious) or This is something you also know.
However, when you add '고' to '알,' it modifies '알' in such a way that it can now indicate knowing in the past and present.
알고 있었다 -already known 너 알고 있었다 - You knew it.
알고 있다 - is known 너 알고 있다 - You know.
A funny thing happens when you try to use 알 with the common tenses of 음니다:
압니다 - I know. I understand. (알아요)
알았습니다 - I understood. I see. I understand. (알았어요)
알겠습니다 - I see. I understand. (알곘어요)
So you see these 'players' can become turncoats depending on the combinations. This is why it is difficult to give a direct simple answer.
I think the question of the meaning of 다는 hasn't been answered yet. I understand that this is a form of indirect quotation, which is used to create an adjective of what was said, as in, "the man who said he was going to leave".
1) 뒷배가 드든하다는 소문 invisible support from behind was strong .... such was the rumor
2) 배고프다는 말 saying that you're hungry
In the example given in this post, 다는 also seems to imply a sense of distance (like the third person creates), from the misunderstanding that happened.
I don't know why, but in the original posting, the first sentence would sound more natural as 알게 될거야 , I'd be pretty confident to say that 알거야 is a contraction for 알게 될거야.
It is also interesting to note that the formation is ㄴ다는 for action verbs, and 다는 for adjectives. 배고프다 above in 배고프다는 말 is an adjective; just check naver where it says [형용사] in its definition. Therefore, 배고픈다는 말 is bad grammar.
I agree the question regarding the use of "다는" in the examples was not fully answered. "는" is such a versatile particle and a component of a large number of 'patterns' that I got confused.
In the examples "다는" is a contraction of "다고 하는" and in the full form "는" still seems to be serving as a tense modifier, although the entire pattern serves (as you said) as a kind of indirect quotation, also marking the preceding clause as adjective to describe (걸) what follows.
In its abbreviated form I don't see "다는" as a pattern standing by itself, but rather there is a statement terminated by the plain style '다' followed by "는+ ~" where '는' accomplishes the function of "고 하는." for example '했' and '있' do not stand alone, but '있다' and '했다' are fine, then add '는+ subsequent clause.'
Anyway, I'm terrible at grammar in both English and Korean, I just try my best to explain things in ways that I hope people will understand. I certainly don't want to be passing along incorrect information, and I deeply appreciate being corrected. Thanks again.
"Vivisection" of language is pretty fascinating to me, but.. ah.. grammar never comes into play when I'm having a conversation. Dare I say, I have never heard a grammatically correct conversation.
Uses of 는:
1. a contrast particle/subject marker
2. a tense modifier
3. used to mark the preceding word/clause in indirect quote
4, used to mark preceding word/clause for adjective case