为什么老师说有give a talk on而没有talk on

为什么老师说有give a talk on而没有talk on give a talk on give a talk on sth. give a talk on与give a talk about各自侧重什么? Do you want to give a talk on that subject The man will give us a talk( on )his country give a talk about/on how to learn english Mr Turner___ ___ (give ) a talk on spaceship next thursday -----____tom____(give)a talk on "zhe life on the go"yesterda a talk on english study__by mr.smith this friday.为什么? English people like to talk on a bus.为什么like后面有个to The man ___________(穿着) a dark coat will give us a talk on m