Can a sentence begin with “But why” or “So why”?

Can a sentence start with ‘But why’ or ‘So why’?

And what’s the meaning and use cases for both of them?

Answer

1. A sentence may begin with but or so or any other conjunction. But for several generations in the 19th and 20th centuries teachers discouraged this use, because it was often misused or overused. Eventually that hardened into a “rule” forbidding the use altogether. It’s really just what I call a baby rule, like “Don’t cross the street unless you’re holding somebody’s hand”: a rule you are given until you’re old enough not to need it. Still, a lot of people, especially schoolteachers and examiners, learned this rule when they were young and never outgrew it. So I recommend you not to use it in tests and graded essays.

2. In questions beginning But why or So why, the but and so mean exactly what they mean in any other circumstances. They are conjunctions, and relate what you say next to what you said just before. But means “What I say next contradicts what I have just said (in some way)”, and so means “What I say next is a consequence of what I have just said (in some way)”.

   Everybody else likes going to the opera. But I don’t.
   Everybody else wanted to go to the opera. So I went, too.

   When these conjunctions are used before a question they imply different motivations for the question. But typically introduces a request for information; so typically introduces a challenge.

   Everybody likes La Traviata, the music is so jolly. But why do they like weird stuff like Wozzeck?

   The reason why people like the very accessible music of hurdy-gurdy-Verdi doesn’t appear to apply to liking the very challenging music of Alban Berg. I’m confused by this contradiction. Please explain.

   Everybody likes La Traviata, the music is so jolly. So why do they like weird stuff like Wozzeck?

   People like Verdi because his music is accessible. In consequence, they should dislike the challenging music of Berg. I demand an explanation of why they in fact do like Berg.

Attribution
Source : Link , Question Author : H M , Answer Author : StoneyB on hiatus