第一个learn前为什么要加to

第一个learn前为什么要加to Do you want to learn to play an instrument?play前为什么要加to? The young girl loves learn to music.这里的learn要不要加S 为什么? Try to sing more English songs,you will find it interesting to learn a foreign language.这句话中learn前为什么加to 第一个序号,那个句子fall down 前为何要加to i want to learn to swim为什么加to from next door副词前不是不加介词的吗?the other后面加了单数=the others吗learn about how to还是learn how togrow up to be为什么要加be,weigh up to就不要加be 请问We should learn to be grateful,为什么要加to be? how to learn English中为什么how后面加to In school it is not easy to learn(a)second language.序数词前不是要加the? I'm going to learn play an instrument.learn后为什么不加to? learning english为什么learn要加ing to be loved前为什么加to what is the sercte to language learning.为什么learn要加ing The teacher wanted me to learn French all by myself 为什么want要加ed 一个小小的英语问题：students learn their lessons in class.they sit in the classroom listening tostudents learn their lessons in class.they sit in the classroom listening to the teacher carefully.这儿listen为什么要加ing呢? It's a great way to learn English to studying grammar.为什么to 后面的study要加ing Let me help you learn English为什么learn不用加to