For those trying to figure out what "das" means:
"Das" means a lot of things in German, so be prepared to learn all it's uses, but I will summarize some of its uses for you here. A lot of these rules can also apply to "die" and "der" as well.
"Das" when used in front a neuter noun such as "Buch" or "Mädchen" usually means "the" in English. So "das Buch" and "das Mädchen" mean "the book" and "the girl" respectively.
"Das" when used next to "ist" or "sind" means "That is" or "Those/These are" respectively regardless of the gender. An example is this very sentence: "That is a boy." Another example that combines the previous section could be "Das ist das Buch." to mean "That is the book." This only applies to "das" and not the other definite articles.
This/These (or even That/Those)
Just like the first example with "the", "das" in German can mean "this" when used next to a neuter noun. So "das Mädchen" can mean "this girl" also. It is important to note however that any definite article can be used this way in German. "Der Mann ist stark" can mean "The man is strong" or "This man is strong." Another example is "Die Frauen sind schön." means "The/These women are beautiful."
LONG NOTE: There is also "dies" and all it's forms which can also be used this way. Though it's mostly used when you are trying to be specific about which thing you are talking about, trying to change formality, or if you're trying to differentiate between "this and that." For instance: "Dieses Buch ist neu. (Aber das Buch ist alt.)" can be translated as "This book is new. (But that book is old.)" Another example I know is from Android: "Dies ist ein Beispiel für Sprachsynthese in Deutsch." to mean "This is an example of speech synthesis in German." Usually context should dictate what sounds better. Using it too much can definitely point you out as a non-native speaker, however.
Just to make things more confusing, definite articles can also mean "that" in the same way it can mean "this" as shown above. Native English speakers might be freaking out right now (I know I did initially), but we do the same thing in English, just to a smaller extent as English inherently demands subject and context in its sentence structure which leads us to using "this/that" rather than "the" usually. Anywhooo, It helps to know that when spoken, stress is usually placed on the article to indicate this particular meaning. An example was used above in the note (das Buch ist alt = that book is old).
(The One) Who/That
This is a more advanced concept of German and is only slightly covered very much later on in Duo, but the definite articles can be used to mean "who" when used as a conjunction. It's weird to think about in English without an example, but here's one: "She is the girl who/that is speaking." is translated as "Sie ist das Mädchen, das spricht."
The grammar involved with using this gets very tricky, so I won't explain much more. Again, any definite article can be used this way. A real-world example (from Facebook) is "Personen, die du vielleicht kennst." which means "People (who/that) you probably know."
Hope this helps everyone out! And have fun learning German!
P.S. all of the different ways of using "das" can get interesting sometimes. "Ich dachte, dass das das Mädchen war, das das gemacht hatte." means "I thought that that was the girl who/that had done that." but that's all taught later! (Though let's be honest, you'll probably never actually hear a sentence like that.) This also shows how crazy the word "that" is in English. Isn't it actually a bit nicer to have different words to help point specific things out in German?
edit: added note about "dies"
edit: added this/that/these/those edit again
I'm trying german for french speakers course, in order to learn one practicing the other. But the quality of information we find here in the courses for english speakers is way much better. I'll be checking here from time to time when I find a hard time there. What a nice explanation on "Das". Danke
I'm confused. It asked me to type the phrase in English. I typed, "This is a boy." and it said I was correct. Here is says that the translation is, "That is a boy." So, is it "this" or "that"? Or does it not matter? Am I overthinking it? i really want to learn and understand German and I want to do it right.
Some languages have a strong distinction between "this thing (near me)", "that thing (near you)", and "yon thing (far from us both)".
English usually treats the last two the same, calling both of them "that".
German goes a bit further and often uses "das" for all of them -- it's basically "that" but can also often be used for "this".
Colloquially, we sometimes use adverbs to disambiguate: "das hier" for "this" and "das Buch hier" for "this book" (literally: this here; this book here), versus "das da" or "das Buch da" for "that" and "that book".
You've put it very well when you say, in reference to the sentence "Das ist ein Junge" that 'it seems "das" here has nothing to do with noun "Junge"'. The rule seems to be that we are to use the neuter pronouns "das" ("that thing"/"those things") and "dies" ("this thing"/"these things") when the thing has not been referenced before in the conversation. The "das" doesn't yet refer to the "Junge". See the comment by mizinamo in the thread started by vagg16.
So “that is a boy,” “this is a boy,” “ that is one boy,” “this is one boy” are all correct?
Those are all possible translations of Das ist ein Junge, yes.
Why is “that is the boy” incorrect?
Because that's not what the German sentence means.
The German sentence says that he is a boy -- any old boy. It doesn't say that he is "the boy", i.e. the one that you and your listener both have in mind, probably because you had been speaking about him earlier.
How would you say “that is the boy”?
Das ist der Junge.
That would mean "That one is a boy" -- i.e. you had already been talking about a group of grammatically masculine nouns and are picking one of them out and saying that that particular one is a boy.
It sounds a bit awkward to me; I'm not sure of a context where that might be used.
When you're introducing something new to the conversation, you use neuter singular das or dies.
Y is it wrong
Since nobody can see what you wrote, references to "it" or "this" or "the right answer" are not helpful.
Please quote your entire answer when you have a question.
Or even better, provide a URL to a screenshot which you have uploaded to a website somewhere that shoes the question, your answer, and the error message if any.
All nouns are capitalised in German.
This is something so fundamental that it's mentioned in the tips and notes for the very first lesson unit - https://www.duolingo.com/skill/de/Basics-1/tips-and-notes
Have you not been reading the tips and notes? Perhaps you're using a mobile app rather than the website https://www.duolingo.com/ ? I highly recommend using the website instead, and reading the tips before starting each new lesson unit.
is it right to write "Das ist ein junge"
No. Mis-capitalisation nouns is just as much a spelling mistake as using a wrong letter. Fliegen (flies = insects) and fliegen (to fly - verb) are different words in German and the capitalisation makes a difference.
Unfortunately, Duolingo does not check for wrong capitalisation. But if you want to learn correct German, you should take care to capitalise your nouns.
"Junge" is "boy" if it is in the nominative case (that is, subject of the sentence) and singular, but otherwise "boy" is "Jungen". This is because "Junge" belongs to a group of nouns known as "weak masculine nouns" which take an "-n" ending in all cases except the nominative singular.
But having written all that I now realise I'm not helping as in "Das ist ein Junge" the noun is nominative singular! Strange that it said "Jungen"! Was it one of the hints? That would explain it because "Jungen" would be relevant to another lesson
All German nouns have gender.
In the nominative case (that is, when the noun is the subject of the sentence) "the" or "that" before a masculine noun is the determiner "der" and "a" (or "an") is the determiner "ein".
Feminine nouns follow "die" for "the" or "that" and "eine" for "a".
Neuter nouns follow "das" for "the" or "that" and "ein" for "a".
In the objective case, masculine nouns follow the determiners "den" and "einen".