He is so full of hot air.

　　他真是满口空话。

　　full of hot air 直译过来就是：“充满了热空气”。在英语俚语中，hot air是“空话，大话和夸夸其谈”的意思。所以这个短语的正确意思是：“满口空话，吹牛，夸夸其谈”。因此，当美国人说"He is full of hot air."时，他/她要表达的意思就是:"What he says is just empty talk."、"He is shooting off his mouth."、"What he says is all jaw."。

　　情景对白：

　　Shirley: He is ready enough with his promises, but often fails to carry them out.

　　雪莉：他总是满口许诺，但常常不履行。

　　Jane: Just ignore him. He is full of hot air.

　　简：别理他，他总是满口空话。

　　搭配句积累：

　　①He is generally regarded as a disgusting guy.

　　大家都认为他是个讨厌鬼。

　　②What he said is simply not credible.

　　他的话一点也没可信。

　　③Never believe in his commitment.

　　千万别相信他的承诺。

　　④Don't listen to him.

　　别听他的。

　　单词：

　　1. be all jaw 全是空话，废话连篇

　　All this could be all jaw without a government that is unified in opinion.

　　如果没有一个思想统一的政府来指导发展，实现这一切只是空谈一场。

　　What he said is all jaw.

　　他说的全是空话。

　　2. commitment n. 承诺，保证

　　We made a commitment to keep working together.

　　我们承诺继续合作。

　　They made a commitment to peace.

　　他们承诺要维护和平。

　　He made a commitment to pay the rent on time.

　　他保证按时付房租。