Using 'wa' in a variety of sentences

• Kore wa nan desu ka. What is this?

  Sore wa kagami desu. That is a mirror.
• Sore wa nan desu ka. What is that?

  Sore wa pen desu. That is a pen.

  Are wa banana desu. That over there is a banana.
• Kore wa yasai desu ka. Is this a vegetable?

  iie, sore wa furu-tsu desu. No, that is a fruit.
• Banana wa nan desu ka. What is a banana?

  Banana wa furu-tsu desu. A banana is a fruit.
• Retasu wa furu-tsu desu ka. Is lettuce a fruit?

  iie, retasu wa yasai desu. No, lettuce is a vegetable.