Ko-S-A-Do Words, are what make up pronouns & the w5 (If you never watched Nick News W5 on nickelodeon, W5 are the Who, What, Where, When & Why. How is also in there too.)

For Now, I’m only going to cover 3 endings. There are 5 or so more, but we didn’t cover those in class.

The table below shos the 4 bases (ko, so, a, do) with the 3 endings (ko, no, re). Do is always a question word. こ Ko talks about someone/something you’re holding or are very close to.  そ So describes something that you are close to but it is farther away than こ.  あ A is always talking about something/someone away from you, say across the room, but is also far from the other person you’re talking to. These change depending on the location of the object to the speaker.

Say I have a pen ぺん.   I would say　これは　なですか？ (Korewa nandesuka?)
The answer would be そらは ぺんです。 (Sorawa pen desu.)

The only one that needs a special note is の.  No is always used with a noun as if to say where is THAT book, not just where are the books. When you’re talking about a specific noun vs that noun in general, you’d use no.

Other than that, they’re just used like in the example above.