Harvesting has begun earlier than usual.变成了How much earlier has harvesting begun? 不是从句成分如果陈述句的吗？如何变了之后，有has，请老师们讲详细点，谢谢，学生基础非常差。
Harvesting has begun earlier than usual.
How much earlier has harvesting begun?
哪来的从句？这是一般疑问句，has 提前了。语序没问题。
先不说语序问题，但就这个句子提问来看，如此提问“时间”，是不能的：
How much earlier has harvesting begun?（误）
答语是什么呢？依据问句答语会是：
Harvesting has begun ten days earlier. 与原句不符，回不到原句的意思。
假如提问时间，就应该依据划线部分提问：
Harvesting has begun earlier than usual.
How early has harvesting begun?（正）