Required / Hidden Placeholder
Does the language require something even if another language would omit it?
含义
A structural slot that must be filled or understood: dummy subject, copula, article, classifier, expletive, pronoun, or support word.
如何识别
Notice places where your language says nothing but the target language needs a visible item, or the opposite.
示例
it|there|do|be|classifier
it rains|there is|do you know
It is raining.
Visual guide
Thought: RAIN Grammar frame: [Subject] + [be] + raining English fills the slot: [It] is raining It = placeholder, not actor
Same idea, slots differ: English: [It] is raining Zero OK: [∅] raining English: [There] is a book Other: [∅] book exists Check required items: subject, be, article, CL, do
语言视角
用母语深入讲解
Mandarin has few dummy placeholders, but some function elements feel “small” yet matter: classifiers, 的/地/得, aspect particles, and required localizers.
我要一杯水。
wǒ yào yì bēi shuǐ = I want one cup water
在所学语言中
英语句子通常需要主语，所以常用 it、there 这类意义很弱的占位词。
It is raining.
it 是英语要求填上的主语占位词，不指具体的人或物。
学习者可能漏掉这种占位主语，或不理解 there is 和 it is 这类句型的作用。
Good transfer potential
This block behaves relatively similarly, so you can transfer intuition more safely between the two languages.