1.speak-说,讲,演讲.作及物动词时,宾语常是表示语言的词.
e.g：Do you speak Chinese?/Mr.Li is going to speak at ourclassmeeting.
2.talk-讲,说话,谈话,与speak意义相近.一用作不及物动词,指一般的谈话或交谈,而不如speak正规的演讲、发言,须跟宾语时,与to、with、about等介词连用.
e.g：Our teacher istalking to（with） the parents.
3.say-一般着重讲话的内容,指有连贯性的说话,通常用作及物动词.
e.g：I don't know what he said.
4.tell-指把一件事情传达给别人或讲述一件事情、一个故事等.常用作及物动词.
e.g：He will tell the good news to everybody in our class.