Das [X] ist [Y] = "The [X] is [Y]"
Das ist [Y] = "That is [Y]"
Das Bier ist kalt = "The beer is cold"
Das ist kalt = "That is cold"
The meaning of das changes whether it stands alone, or is attached to a noun (it must be a neuter noun).
So how to say "That/this beer is cold"? With dies. It means both "this" and "that" when used with a noun. However, dies by itself means "this":
Dies ist kalt = "This is cold"
When you want to put it with a noun, you must put the matching ending on it (called declining) to match das (because Bier is grammatically neuter), you can say:
Dieses Bier ist kalt = "This/that beer is cold"
Duolingo teaches how to decline adjectives and so on in later lessons :)
Well, let's first look at the conjugation chart for this verb:
ich schmecke = I taste
du schmeckst = you taste (sg.)
er/sie/es schmeckt = he/she/it tastes
ihr schmeckt = you taste (pl.)
wir/sie/Sie schmecken = we/they/you (pol.) taste
These are all the forms of the verb in simple present tense. So we need to choose one of them, right? So how do we choose? Well, if we're not using a personal pronoun (literally saying "it tastes" or "they taste", etc.) then we're usually using a noun directly ("the beer tastes" or "the beers taste"). Notice that even in that English example, the form of the verb is different whether the pronoun is singular/plural, but also whether the noun is singular/plural - and they match up with each other.
So what's happening is that when you use a singular noun, use the verb form for er/sie/es. And when you use a plural noun, use the verb form for wir/sie/Sie. In grammar jargon, these are called the third-person singular and third-person plural conjugations.
If you're ever unsure which one to use, just think about which pronoun you would need if you swapped out the noun: e.g. you could turn "the beer tastes good" into "it tastes good", but not "they taste good" or "you taste good". So that tells you you need to use the "it" = es form of the verb here.
There has been a different discussion for this post. Anyway, here are few tips to understand them. die, der, das are articles and used before noun. Die is used for Feminine, Der for Masculine and Das for Neuter, but still it's always a good practice to learn the Nouns with article. eg. Madchen (girl) is feminine but considered as Neuter Gender in German, therefore it is Das Madchen. Die is also used for Plural Nouns.
Nouns are defined as Nominative and Accusative case. eg. The man eats the apple. Der Mann isst den Apfel.
Since Apfel is Masculine, therefore the article 'der' is changed to den in accusative case. Here is the matrix for the same.
Nominative Case -
Further example - An Apple - Ein Apfel.
A man eats an apple. Ein Mann isst einen Apfel.
A pizza - eine pizza
A man eats a pizza. Ein Mann isst eine Pizza.
Now, since pizza is feminine in German, therefore the article (eine) remains same in accusative case.
Hope this helps :)
'The beer is good' might convey the same idea as 'Das Bier schmeckt gut' but it is simply not the appropriate translation in a lesson about learning German instead of an exercise in lateral thinking. Maybe you need to realise that 'schmeckt' actually means 'tastes' instead of 'is'.
It tastes good: I like the taste
It is still good: it is still safe to drink and has not turned sour or dangerous // it is good for you: it helps your health // it is good: (perhaps) it has some positive qualities in a greater amount than other beers, without saying what those qualities are (health? taste? colour? weight?).