Translation:This above all: to thine ownself be true.
I don't remember now. I tried a few things and all were wrong. I think most of them included: "...be true to yourself". Maybe one was - "don't be dishonest with yourself". The first one included the word mission. Another the word "task". If it happens again, I'll let you know.
I had done a quick check with a search engine and all the websites that came up had it as two words. Now I have gone and checked the actual text of the play, and, indeed, there was no space. I will remove it again.
What happens in Duolingo when you add the space into your answer? Does it mark it wrong or count it as a typo? Do we need to add a variation with it separated into two words?
I don't know where you checked "the actual text of the play", but the First Quarto, Second Quarto and First Folio all spell it "owne ſelfe" (the first has "thy" rather than "thine"), while the three modern editions of Hamlet I happen to have in my house all have "own self".
(Scans of facsimiles of the early editions can be seen at http://internetshakespeare.uvic.ca/ if anyone wants to check.)
I don't think there's any error in the Klingon. And we accept a few different versions of the English, but are always willing to add more if someone thinks we've missed some legitimate translations. However, I think we will continue to accept the more direct and literal translations as alternatives and have Duolingo show the Shakespearean line as the "best" answer.
"This thing at the area above everything"? There are a few reasons it doesn't work well. For one, we don't know that Doch works well for a concept like "don't deceive yourself." Secondly, I'm pretty certain that Klingon does not use the idea of "above" to mean "more important/to be considered first". And then there's the unlikelihood of applying a locative to a noun. If you used this as the object in a sentence, I would assume that "above everything" was the location of the action and that "this thing" was just the object of whatever verb comes after it.
Not quite. "Mission one" would be Qu' wa'. Here the wa' is counting the missions, so limiting the number to only one. A direct translation would be, "One task is very important." The -'e' is the most complicated part to translate. You might say, "As for one task, it is most important," or, "ONE TASK is most important," or even, "one task, and nothing else, is most important." Though that last one might be better expressed with a neH after Qu'. In fact, if I were translating this I might have put a neH there.
Is it the -'e' that confuses you? It's not absolutely essential here. Try this:
potlhqu' wa' Qu' One mission is very important.
wa' Qu' one mission is the subject.
potlhqu' it is very important is the verb.
It's just like any other basic sentence. All the -'e' does is focus attention on the wa' Qu' one mission.
This phrase is not a good example of how to translate between the languages. It is probably OK to have a few of these in the course, but it's not a great teaching tool. Since Klingon has no way to say "this" without identifying what "this" is, you have to get used to specifying. You can say things like, "this thing" or "this idea" or "this task", etc. It's nice that English allows you to leave it very general and non-specific, but Klingon requires you to be very specific in this particular case.