（1）构成完成时态和完成进行时态：
Great successes have been achieved on all fronts. 在各个战线上都取得了巨大的胜利。
That was the place I had been longing to see. 这是我一直渴望见到的地方。
（2）和动词不定式构成谓语，表示不得不做的事情：
The train has left.We’ll have to wait for the next train. 火车开了，我们得等下一班车了。
Do we have to translate the whole text into Chinese? No,you don’t have to. 我们需要把整篇课文译成汉语吗？不必。