[Grammar] Adverbial clause vs noun clause

[toloue_man]

Of the following sentences, the first is an adverbial clause and the second is a noun clause. What is the difference between these two sentences that we name the first one an adverbial clause and the second one a noun clause?


1) Whoever knocks at the door, don't open it.
2) Whoever broke the window must pay for it.

And another question, what kind of adverbial clause is the first one?

 

[Tdol]

What are the subjects of the two sentences?

 

[Mensu]

1) Whoever knocks at the door, don't open it.
Adverbial Clause of Concession.

Since it is an imperative, the subject "you" don't appear, so the sentence "don't open it" itself is complete.
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2) Whoever broke the window must pay for it.
Noun Clause

In this sentence, "Whoever broke the window" clause works as a noun, like "anyone", "the person".
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As a rule of thumb, you can rid the sentence of the confusing clause. If it is still complete or acceptable, it could be an adverbial clause. If it is not, it will be a noun clause.

Whoever knocks at the door, don't open it. → Don't open it. √
Whoever broke the window must pay for it. → Must pay for it. ×