Formal logic is definitely tricky. It's less common than it used to be but it might still pop up in a question or two. Any predictions we have are just based on recent trends but the LSAT can always switch things up a bit! As for how much time you should spend on it, part of that depends on how well you have mastered other topics. If you have mastered LR in general and are currently only missing 1 or 2 questions per section, then you probably do want to spend some time on formal logic. But if you need more of an improvement in LR, you get more bang for your buck investing your time elsewhere. For example, Flaw, Strengthen, Assumption, and Must Be True questions are super common so if you are struggling with any of those question types, that's what I'd prioritize.
The problem with formal logic is that there's not really an express way to learn it--it typically takes some time to master. Which is why the 1 or 2 questions that involve it is not usually worth the time investment it requires. We do have a chapter about it in our Logical Reasoning Bible and our full-length courses include materials on it. But it's not something that can really be fully covered in a blog post. When you encounter formal logic, think closely about the difference between all (
), most (more than half,
), and some (at least one,
Check out this Crystal Ball Webinar for some general predictions about the upcoming tests: https://blog.powerscore.com/lsat/crysta ... recording/
Hope this helps!