want用法：
1.想干什么want to do sth
They want to join the sports club. 他们想加入运动俱乐部。
2.第三人称单数作主语，want要作变化
①He wants to play basketball.
②Li Xia wants to play the piano.
3.变疑问句，否定句要借助助动词do或does.
①-Do you want to play soccer ball ? -Yes , I do . / No , I don’t.
②-Does he want to go home by bus ? -Yes , he does . / No , he doesn’t