英语中已动词开头的词语,什么时候用do?什么时候用to do?什么时候加ing...答:有些动词后面只接不定式,也就是to do 如 hope, wish, help, decide, ask, learn, teach, choose, agree, plan, encourage, tell, use, invite, send, fail, refuse, offer, afford, preptend, promise, 以及词组would like, get/be ready, do/try one’s best, make up one’s mind等...