The goal of every sentence is to convey its point as clearly and effectively as possible.
That’s it.
The difficulty is that to their author sentences are pretty much always clear – you’re the one writing them, so you know what they mean. But from the page just previous you know that good writing isn’t about what you understand; it’s about what your readers can understand. This means that you can’t stop at “I understand it, so it’s fine.”
The fact is that your first draft is probably not going to convey information as clearly and effectively as possible (which is the goal, remember?). And for most writers, even very advanced ones, the common block on the road to clarity and effectiveness is word order.


