Dore des' ka? = Which is it?
Kore des' ka? = This (near you) is it?
Hai, sore des'. = Yes, that (near the person spoken to) is it.
Iie, are des'. = No, that (away from you and person being spoken to) is it.
Kore, Sore, Are, and Dore are pronouns, that means they act as a noun. Kono, Sono, Ano, and Dono are just like Kore, Sore, Are, and Dore, but are used before a noun. Example: Kono usagi. (ko-no oo-sah-gee) "This rabbit." Sono piza. (so-no pee-zah) "That pizza." Ano hito. (ah-no hee-toh) "That person." and, Dono neko des' ka? (doh-no neh-ko des ka) "Which cat is it?" That's not so hard to learn, once you know the "ko-so-a-do" system.
Before we wrap up this lesson, let's cover one more group of words that uses the same "ko-so-a-do" system. You already learned 2 of them our last lesson, Doko (Doh-koh) "Where", and Koko (koh-koh) "here". Since you know those 2, you should be able to figure out how to say "there" (near who you're speaking to) and "over there" (away from both of you). Soko (so-koh) and Asoko (ah-so-koh). OK, maybe you didn't guess "asoko", but you can still see how it works in with the system, right? let's review:
Doko des' ka? = Where is it?
Koko des'. = It's here.
Soko des'. = It's there.
Asoko des'. = It's over there.
Sono usagi, dare des' ka? = That rabbit, who is it?
Kono usagi, Usa Hime des'. = This rabbit, it is Princess Usa.
Dono shima des' ka? = Which island is it?
Ano shima. = That island (over there).
Practice these; see what other sentances and questions you can make up from the words you've learned so far. I hope these lessons are fun as well as educational, but don't let that stop you from learning more Japanese from other places.