As a quick rule of thumb, tud in the sense of knowing something factual or knowing an answer (as opposed to its other main use knowing how / being able to do something) is almost always definite. The logic behind this is basically, "Do you know [the answer]?" or "I know [the fact]".
With all verbs, a clause counts as a something definite, for verb conjugations. Often, there is a "stand-in" word (most commonly azt) in the structure which makes this obvious:
Azt eszem, ami az asztalon van ("I eat what is on the table" or "I eat that which is on the table")
Azt látom, hogy ég a házad. ("I see that your house is burning" - doesn't sound like the verb "see" has a definite object in English, but in Hungarian it does)
Azt tudom, hogy van itt valahol egy ceruza ("I know [the fact] that there is a pencil here somewhere.")
But lots of sentences with tudom don't bother to include the azt. So you get things like,
Tudom, hogy fáj ("I know that it hurts")
which doesn't have any apparent word as the object for tudom but the object is the following clause, and the sentence could be written more fully to make that explicit: Azt tudom, hogy fáj.
Incidentally, I see that I'm starting to get into the part of the course where it's "guess which one possible wording is accepted (so far)" territory.
I wonder how the people who got further than this managed to do it while retaining their sanity. Keeping a notepad with the currently-accepted wordings somewhere to copy and paste?
I see a good deal more reporting in my future.
(Plus I'm really not looking forward to all those odd sentences once the cases start appearing.)
For a language "utterly logical" their speakers failed to create a course that is even close to anything I would call logical in many regards.
Everything makes sense? Every rule seems to have exceptions. We use azt unless we don't bother... That is not chess but any game were rules are bent to make a child happy.
So, I can not really agree. Hungarian has a nice sound due to vowel harmony, but its grammar is a mess like probably in all languages.
At least for this example....the explanations are from lessons way in the future, not at the present moment. I am 2/3 of the way through level 2 and there has only been ONE instance where "azt" has been used. I have seen it on this page far more than I am ready to see it!
"Do you know it, why?" sounds just as wrong to me in English :)
And ..., hogy miért also sounds illogical to me, since in the languages I had learned so far, "why" can start a relative clause by itself.
Perhaps I'll have to think of it as something like "Do you know the following: why .... ?".
Oops, sorry, I thought it made sense. :D I was still thinking in Hungarian, it seems.
Now that Jsiehler made it clear, there's not much for me to add. But that "hogy" isn't necessary in Hungarian either, but can be added whenever the conjunction is originally a question word:
- "Tudod, hogy mikor indulunk?"
- "Látni akarom, hogy mennyit csináltál."
"Azt" is similarly optional in these sentences (but the definite conjugation is necessary in the first clause).
I learned something early on that has served me very well over the years. It is about when to use "what" "which" and "that". It is specifically about the word "what", when it is not a question word. It is a simple test, to decide whether the usage of "what" is correct.
The word "what", when it is not a question word, can ALWAYS be replaced by these words: "the thing that". If you are not sure whether to use "what", substitute the words "the thing that" in the sentence. If it does sound correct, "what" is to be used. It never failed me.
"What I said is correct" - "The thing that I said is correct"
"I don't know what you mean" - "I don't know the thing that you mean".
And so on. All correct sentences. I am not saying they mean the same thing (they do), but they are all correct. So, the use of "what" is correct.
"Yogurt is delicious, what is a surprise" - "Yogurt is delicious, the thing that is a surprise".
Oops... Incorrect. Seriously, it works perfectly.
But the point I am trying to make here is this: the word "what", as "THE THING that" has an implied, built-in, definite object. And that is what makes it a definite construction.
And this is equally true for all the other similar words ("where", "why", "who", etc.). They all have this built-in definite object, even if it may not be so easy to put into words. Because they don't have their own specific satellite words like "what" does in "that". But the concept still stands.
"where" - "the place where"
"why" - "reason why"
"who" - "the person that/who"
So, "tudod" in the sentence above is addressing that implied direct object hidden in the "W" word.