Ever, wondered, how, NOT, to, use, commas?
 So, you read the first blog (about comma uses), you are back for more.
 My blog, about commas, hopefully entertained you.
 Blogs, such as this, are hopefully both informative and entertaining.
 I wrote the blog, and hoped you would read it.
 You can write a blog about commas not just for pleasure, but also for learning.
What do these sentences have in common, I hear you cry? Yes, they’re all grammatically imperfect (well, some are more wrong than others, depending on the context).
Want to know more? Okay, if you insist:
 This is a comma splice. The comma is not ‘strong’ enough here. Corrections include: So, you read the first blog and are back for more. So, you read the first blog, and you are back for more. Or even: So, you read the first blog; you are back for more.
 Actually, this one is both wrong and right. My meaning was: Because I have written several blogs, my blog about commas is one of many, and I hope it entertained you. I could have said: My blog about commas hopefully entertained you. Or (to keep the commas): My last blog, which was about commas, hopefully entertained you. However, because there is always flexibility with the English language, and different contexts require different tones, you could actually use  as it is. As long as you know the ‘rules’, you can play with them.
 I meant here that blogs such as this one (as opposed to a technical blog, which might not be entertaining but might be informative) are (hopefully) informative and entertaining (you must be the judge of that). Because of the commas, you can remove ‘such as this’ (a non-restrictive clause), and you then imply that ALL BLOGS are informative and entertaining, which is unlikely. Some will be neither informative nor entertaining. Commas matter.
 This is one of my ‘comm-obsessions’, a compound predicate, where a subject is shared by two or more verbs. The gold standard is not to insert a comma between the elements of a compound predicate, although you can to avoid ambiguity. For example, she recognised the cat that entered the room, and gasped (she gasped, not the cat). So, example  should read: I wrote the blog and hoped you would read it. Or (keeping the commas): I wrote the blog, and I hoped you would read it. The first one is more informal, obvs.
 Finally, commas are not generally used with correlative conjunctions (either/or, neither/nor, whether/or, both/and, not only/but also). This should read: You can write a blog about commas not just for pleasure but also for learning. Unless, of course, you put a comma after ‘commas’ and before ‘not just’, which would work too, in my opinion, because what follows is arguably non-essential. You can write a blog about commas – anyone can.
You see, there are ‘rules’, but they can always be broken.