英语中有多少从句?

太多了,一、名词性从句其中又包括主语从句、同位语从句、宾语从句、表语从句What I have is only a piece of bread。(What引导的主语从句)News spread in the village that he came back。(that引导的同位语从句)I think that you are right。(that引导的宾语从句)What I appreciate is that you are brave。(that引导的标语从句)二、形容词性从句也就是定语从句The mountain is beautiful from the top of which we can see our school。(which 引导的定语从句)三、状语从句主要有时间状语从句、地点状语从句、原因状语从句、条件状语从句、目的状语从句、让步状语从句、比较状语从句、程度状语从句、方式状语从句、结果状语从句I will call you as soon as I arrive in Beijing。（as soon as引导的时间状语从句）You should have put the book where you found it。(where引导的地点状语从句)I hate you because you hurt me。(because 引导的原因状语从句)If it is convenient,I will help you。(if引导的条件状语从句)You must speak louder so that you can be heard。（so that 引导的目的状语从句）She passed the examination though she had not studied very hard。(though引导的让步状语从句)She finds it easier to read than to write．（than引导的比较状语从句） 再问： 怎样可以判断它们是哪种从句