In Japanese, when do we use は and when do we use は ? Actually I am writing two sentences: 1. かれははしつています 2. かれらはカタカナをかいています Where in the first sentence there is a は at the end of かれ. While in the second sentence, except for the は behind the かれら, there is still a を at the end. Can't I just say かれらはカタカナかいています?Why there is a を there? I just begin my Japanese lesson and it is fun! Can anyone help me with that?