Are you on mobile or desktop? I found Duolingo infuriatingly low on explanations for anything until I realised there's a desktop site with tons of explanation, charts etc. As for why that isnt included in the mobile app... I dunno. I guess it's supposed to be lightweight or something but it feels pretty crippled in comparison.
There are no charts for pronouns on website. I wish they would've provided like they are providing for verbs.
The application and website have one con each; microphone may not work on websites(lot of users have complained about this) and you will not get charts for verbs on mobile app. Right now I am using both, learning through website and practicing through app.
'cow' is feminine and so takes the feminine form of 'your'. See https://www.duolingo.com/comment/1363964/Dein-Deine-Mein-Meine
Back ages ago, thy was the possessive form of thou (the objective case is thee), which was an informal singular "you" in English. However, these days English speakers mostly encounter forms of thou in antiquated texts such as in Shakespeare or the King James Version of the Bible, suggesting the erroneous impression that "thou" is/was more formal.
So, yes, "thy" means the same thing as dein/deine, but it might not be the clearest translation choice for many audiences. And there really isn't a good way to convey formality/informality of "you" ('tis called a T/V distinction: http://en.wikipedia.org/wiki/T%E2%80%93V_distinction ) in present day standard English.
What you typed is incorrect because the sentence translates to "is that your cow". Das can mean both the (only in neuter nouns, cow is feminine) and that.
What you typed would translate to "ist es deine Kuh" or "ist sie deine Kuh" (when it is a feminine noun, it is better to use sie for it).
The 'tips and notes' grammar section on the desktop version of Duolingo says as follows:
Demonstrative Pronouns in the Nominative Case
The demonstrative pronouns in English are: this, that, these, and those. In German, the demonstrative pronouns in the nominative case are the same as the definite articles. That means, "der," "die" and "das" can also mean "that (one)" or "this (one)" depending on the gender of the respective noun, and "die" can mean "these" or "those." For example, if you talk about a certain dog, you could say "Der ist schwarz" (that one is black).
'Kuh' is feminine, can somebody explain why it's not
The child = Das Kind / That is my child = Das ist mein Kind / This is the child that I love = Dies ist das Kind, das ich liebe.
"Das" always refers to a noun (here: Kind)
I hope (that) you understand = Ich hoffe, (dass) du verstehst
"Dass" is a conjunction, that can often be dropped.
"Kuh" = cow (female), a "Rind" can be a cow, a bull or an ox.
In Nominative and Acussative case is the same inflection Neuter=dein;femenine=deine,plural=deine. Only changes the inflection in Masculine Nominative male=dein Acussative male=deinen
Dative (male/neuter)=deinem Dative (female)=deiner Dative (plural)=deinen
Genetive (male/neuter)=deines Genetive (female/plural)=deiner
I hope that helps
Since "Das" and "deine Kuh" are connected by a form of "sein" (English equivalent "to be") "deine Kuh" is nominative, not accusative. By the way, "conjugate" is for the forms of a verb; for nouns, pronouns, and adjectives one has "declensions", not "conjugations" - one "declines" a possessive adjective like "deine", not "conjugates" it.
No -- if you want to specify that it's male, you have to use a different word, depending on whether it has been castrated or not: dein Bulle (your bull), dein Stier (your steer), dein Ochse (your ox).
The word Kuh is grammatically feminine and may refer either specifically to a female cow, or (perhaps a bit colloquially) to cattle in general if the gender of the animal is not important.
There is also das Rind, which refers to a cattle animal regardless of gender.
What is the difference between deine and eure? Or dein and euer?
dein, deine is something that belongs to du -- one person whom you know well and whom you are speaking to.
euer, eure is something that belongs to ihr -- several people whom you know well and whom you are speaking to.
It's like the difference between "my" and "our", or between "her" and "their" -- is the possessor one person or do several people own the noun?