叫從句沒那麼高大上，其實條件狀語從句就是我們小學裡學的“如果就”和“只要就”句型。它表示的是一件事實現之後，另一件事才會發生的情況。

條件狀語從句最主要的引導詞是if，if可以引導真實條件句和虛擬條件句。

If之外，還有unless, in case, on condition that, provided, 還有隱含條件關係的but for，without等。

If

真實條件句

If he buys a house in the city this year, I will approve of your marriage. 如果他能在市裡買套房子，我就能同意你們的婚事。If there is no rain within 10 days, the drought will kill the crops. 如果十天內不下雨，莊稼會渴死。

虛擬條件句

If he could buy a house in the city this year, I would approve of your marriage. 他今年在市裡買了房子我才能同意你們的婚事（其實他根本買不起）。If I were you, I would study harder. 如果我是你，我會更努力得學習。If you had come earlier, you should have caught the train. 如果你來早點，你就趕上火車了。Unless

Unless=if not.

We will not go unless you arrive. 你不到，我們不走。You cannot sell anything unless you give it a value. 任何東西，除非有定價，才能被買賣。In caseIn case you need me, call me. 如果你需要我，打電話就好。You can count on me in case he bullies you. 如果他欺負你，有我呢。On condition thatI can help you on condition that you do not ask me to help you again. 如果你以後不再找我幫我，我就能幫你。He will surrender on condition that his wife and child are safe. 如果能保證妻兒安全，他就會投降。Whether or notHe will not come to our party whether he has the time or not. 無論他有沒有時間，他不會參加我們的聚會。

還有其它的情況，不一一列舉。只要是滿足某條件，某事就發生的型別，都可以算作條件狀語從句。

壯語從句，是指句子起壯語作用時，同副詞作用同，這樣的句子叫壯語從句，又叫副性從句。主要用來修飾動詞，可分，A，時間從句，B地點從句，c原因從旬，E條件從句等

壯語從句就是原來初，高中接觸到條件複句，假設複句，祈使句類同(我自已理解，如果有不當之處敬老師們指正)我學的時候，劃分句子成份是這樣。