Harvesting has begun earlier than usual.變成了How much earlier has harvesting begun? 不是從句成分如果陳述句的嗎？如何變了之后，有has，請老師們講詳細點，謝謝，學生基礎非常差。

Harvesting has begun earlier than usual.

How much earlier has harvesting begun?

哪來的從句？這是一般疑問句，has 提前了。語序沒問題。

先不說語序問題，但就這個句子提問來看，如此提問“時間”，是不能的：

How much earlier has harvesting begun?（誤）

答語是什么呢？依據問句答語會是：

Harvesting has begun ten days earlier. 與原句不符，回不到原句的意思。

假如提問時間，就應該依據劃線部分提問：

Harvesting has begun earlier than usual.

How early has harvesting begun?（正）