orukeのプロフィール

いつもお世話になっています。 中学３年生で受験があります。 Kiyoshi: Dad, do you use your cell phone every day? Father: Yes, because I have to keep in touch with others for business. Kiyoshi:Is it cnvenient?　　 Father: Oh, yes. But it is not (　used 　) for talking only. We can also use it for e-mail and the Internet. Kiyoshi: Then, what are the problems when people use their cell phones? Father: Well, I think some people have bad manners when they use them. I don’t use a cell phone in a public place. Do you want to have one someday? Kiyoshi: Yes. の会話のなかの( )内のused　なんですが、なぜ過去形になるのでしょうか。 英語が苦手です。よろしくお願いします・