it can be后来为什么不能加doing

供参考
单以 It can be ...来说
後面可以是 ing的
例如
It can be running well.
至於後面该是些什麼
应当是 以 be 这个字为准
be 字後面可以有什麼
便可以有什麼
原帖提及不可以加 doing
请提供多些资料(语境)
也许能够补充一些意见It can be useful to write a short summary after reading a passage , because it will be of great use to your writting. 我们老师说It can be 只能加adj 或done ，为什么不可以加ing?以這句來說(It can be useful to write a short summary after reading a passage )It 在這裡其實代表了 (to + ... )換句話說原句可以改為To write a short summary after reading a passage can be useful.這是常見的基本結構 It + be + adj + to + ...大概是這原因你的老師提及‘要用adj’但單就 can be 來說後面跟~ing是可以的也是常見的以下是2個網上的例子(網址用Hi傳給你供參考)***********例一FEC Chair: 'We Can Be Doing More On Disclosure' After Citizens UnitedJune 10, 2011The chair of the ..."From my personal perspective, I think we can be doing more on disclosure and I think we should be," FEC Commissioner Cynthia...例二3 Things you can be doing to help people recognize your brand************至於為何提及‘done'一時間想不到有任何理由如還有疑問請再提出看看是否幫得上忙我想问一下，你的例句中Things you can be doing to help people recognize your brand是什么意思？还有，你想到为什么加done了吗？谢谢。也許可以在這裡簡單的說一次can be 其實是 [ be ] 的其中一種在語法上(不理會意思)與 is/are/will be/shall be...等相同因此能夠作為(1) 完整的動詞He is a good boy./ He can be a good boy.(2) 助動y詞即後面可以加~ing 例子已提供了(3) 被動式中的 beHe can do it./ It can be done by him.至於為何你的老師會提及 done也許當時他想及‘被動式’Things you can be doing to help people recognize your brand如果你有上那網站應當看見這是‘標題’標題因為要吸引注意所以句子結構可能會與一般接觸到的不同這裡用了‘倒裝’原句可寫成You can be doing things to help people recognize your brand由於要強調 things 所以移至句首意思是你可以做的有助讓(help)人們認得(recognize)你的品牌(your brand)的事情(things)