English has several different strategies for asking why. The most obvious is just to tack why onto the start of a sentence and leave it at that: Why is it snowing? Why did you leave?
But there are more interesting options. How come it’s snowing? How come you left? The meaning of this is pretty similar to plain why, but the word order is different. If you simply replace the why in a why question with how come you end up with a deeply non-native sounding sentence: *How come is it snowing? *How come did you leave?
Yet another strategy to ask why involves what for, as in What did you leave for? But here the meaning is a little different. Trying to ask why it’s snowing this way reveals the problem. You can certainly ask What is it snowing for?, but it suggests that you think the weather might deliberately be trying to spite you. And again, the word order facts are surprising. If you’re misguided enough to follow the old-fashioned grammatical injnction against ending sentences with prepositions, you’ll be forced to ask For what did you leave? and For what is it snowing? Even the most dyed-in-the-wool pedant would have trouble claiming that this is a stylistic improvement.
Then there is the how that sometimes can mean ‘why’, mentioned in other posts below, and reflected in our lab’s publications on Dutch hoezo and what we’re calling propositional how in English: How is it snowing right now? How is it that you left? But this doesn’t just mean why either.
That’s at least four ways to ask why, with various subtle differences among them. But this is nothing compared to German, which provides an astonishing richness of options—so many, indeed, as to deserve a separate blog post.
by Marcin Morzycki