賓語從句意思表達缺少某事,某物,某職業(yè),某年齡,某價格等時都可以用what
如：Can you tell me what this is? 某物
Please let me know what you can do?　某事
I don't know what his father is.　　某職業(yè)
Now, please tell me what your age is.　　某年齡what的概念叫聯(lián)系代詞,代詞在單句中的成分主要是主語,賓語或表語,也就是說,從句表達不完整,在成分方面缺少主語或賓語或表語,從意思上,缺少以上幾方面的意思時,就是用what引導(dǎo)賓語從句的情況了