It doesn’t matter what the sentences you practice with say; it doesn’t matter what their content is. In fact, the less interesting the sentences are in their own right the more useful they are as vehicles of instruction, because, as you work with them, you will not be tempted to focus on their content and you will be able to pay attention to the structural relationships that make content—any content—possible. The conventional wisdom is that content comes first—“you have write about something” is the usual commonplace—but if what you want to do is learn how to compose sentences, content must take a backseat to a mastery of the forms without which you can’t say anything in the first place. To be sure, your eventual goal is to be able to write forcefully about issues that matter to you, but if you begin with those issues uppermost in your mind, you will never get to the point where you can do verbal justice to them. It may sound paradoxical, but verbal fluency is the product of hours spent writing about nothing, just as musical fluency is the product of hours spent repeating scales.