請問這是 "子句" 還是 "補語" 呢??

先給你一個虛擬的對話情境:

A: What is plasticizer (塑化劑)? (甚麼是塑化劑?)
B: What did you say? I can’t hear you！ What is it? (你說甚麼? 聽不清礎！甚麼碗糕？)
A: My question is what plasticizer is? 或 The question is what plasticizer is. (我的問題是甚麼是塑化劑) What plasticizer is 是個不能獨立存在的句子 因此是個子句 (就像小孩句子還不能獨立) 並且是個 名詞子句 (註: What is plasticizer? 才是完整可獨立的句子)
當然你如果非要弄清礎它是否是個補語 那麼What plasticizer is也算是主詞的補語 (只是與其花這個力氣 不如把它用在瞭解上述句子的演化過程) 到這裏如果你都懂 特別是最後一句的語意及句型結構是怎樣來的 那麼你原句The question is what the formula of K and M is . 的語意及句型結構也和它相同 如果你還想知道主受詞補語 就請參考我給你另一提問的解答例句 加油!

"子句" 包含完整主詞, 動詞及連接詞

what: 連接詞
the formula of K and M:主詞
is: 動詞
"what the formula of K and M is" 是 "子句"
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"補語" 不包含完整主詞, 動詞及連接詞
如
The boy with long hair is my son.
" with long hair ": 主詞補語
Please give the book to Jack wearing blue hat.
"wearing blue hat": 受詞補語