"Son tus calcetines."
These are = "estos son" They are = "ellos son" or just "son" In Spanish it's normal to drop the "ellos" as it is implied, but you can't just say "are" in English because there's no way of knowing the difference between we are, you are and they are.
Thank you. That makes much more sense. Although when translated into English, saying "they are" instead of "these" or "those" sounds rather silly. I guess it varies from language to language.
I also put "Those are your socks." because "They are your socks" sounds ridiculous to me. "They" implies an animate object such as a person or animal. It is grammatical example that sounds as ridiculous as the conceptual example of a spider drinking milk. But I suppose the comment from iakobski explaining the concept of "Son" without a prefix is assumed "Ellos son" makes this easier to accept. However, it would behoove the developers of this application to pay closer attention to these nuances and be kinder to their users.
Because it is a commercial spelling, a kind of shorthand. The same way that nite is not a correct spelling of night.
I said "that's your socks", I believe you can say that in English can't you?
No, that is not correct usage because "That's [that is] your socks" mixes a plural noun (socks) with a singular conjugation of the verb and pronoun (that is).
...but people do say it. It is informal, and Duolingo is correct not to accept it as a translation, but you aren't imagining things.