So your primary forms of communication these days are emails, Slacks, and Zoom chats, but you haven’t had a grammar lesson since Britney Spears wore matching denim with Justin Timberlake and the ocean levels were just beginning to rise.

Look, writing is a hard. As an instructor of college writing courses with 10 years of experience studying the weird cognitive processes that go into putting words on a page, I know the laundry list of problems that could throw off your flow. Maybe you’re sleep-deprived or vitamin deficient. Maybe your tired eyes can’t focus on the screen. Maybe your brain interprets letters and language differently from the rigid model of a neurotypical student on which standard education is based (and which results in U.S. literacy rates falling below average of comparable nations, like Canada, Japan, Korea, and all of Scandinavia).

But what I’ve learned as a writing instructor is that most of these problems (though not all) can be easily helped with a little technology and effort. Free programs like Grammarly can scan your writing for punctuation, spelling, and grammar errors. If your writing style consists of poor syntax (i.e. messy sentences that lack structure), a simple program can highlight and explain your mistakes.

To be honest, when I first started tutoring ESOL (English for Speakers of Other Languages) students, I told them not to use those types of programs because I thought they simplified their writing. Then, when I started teaching college writing courses I scoffed at those programs because I thought it encouraged students to be lazy about their mistakes.

I was wrong. As bad as clichés are, it’s true what they say: Work smarter, not harder.

Why? Because grammar is a game. We’re all expected to play along, but the rules are unnatural and they take time to learn; no one speaks the way that they write, and no one should write they way they speak. Ultimately, the open secret is that grammar is dumb. It’s just a system of rules that we all agree to follow in order to communicate clearly. But when you have a plethora of free tools like autocorrect and Grammarly and you don’t bother to use them–well, at some point, it’s just rude.

Based on 10 years of working with writers of all levels, from non-native speakers to college freshmen to CEOs of banks, these are the five most common grammar mistakes and what they reveal about you as a person.

Grammarly

Sentence Fragments

What Is It: “Put simply, a sentence fragment is a clause that falls short of true sentencehood because it is missing one of three critical components: a subject, a verb, and a complete thought.” –Grammarly

Example of Being Rude: “There are many ways to frighten little brothers. For example, by hiding under their beds and waiting for dark.”

Example of Not Being Rude: “There are many ways to frighten little brothers. For example, you could hide under their beds and wait for dark.”

Who Uses Sentence Fragments: Honestly? Sentence fragments scream that you do not now, nor have you ever once, given a f*ck about other people’s lived experiences. I don’t believe you’ve ever held the door open for the person behind you, and you probably text people to cancel plans at the last minute.

Misused Semi-colon

What Is It:“The most common use of the semicolon is to join two independent clauses without using a conjunction like and.” – Grammarly

Example of Being Rude: “We can go to the museum to do some research; pretty quiet there.”

Example of Not Being Rude: “We can go to the museum to do some research; it’s pretty quiet there.”

Who Misuses Semi-colons: You care about self-improvement and aren’t afraid to fail. You probably do yoga and/or pranayama breathing. You subscribe to The New Yorker but only read the headlines.

Grammarly

Run-on Sentences

Example of Being Rude: “Lila enjoyed the bouquet of tulips John gave her on prom night however she prefers roses.”

Example of Not Being Rude: “Lila enjoyed the bouquet of tulips John gave her on prom night; however, she prefers roses.”

Who Has Run-on Sentences: You’ve probably been called a “flake” by your friends after canceling too many plans at the last minute–or, more typically, you forgot you had plans in the first place because you got distracted and had to send an apology text three hours later. You often interrupt people when they’re speaking, not necessarily because you’re opinionated but because you’re over-excited to respond.

Comma Drama (Missing Commas, Misused Commas, Oxford Comma, etc.)

What Is It:“Some writers think of a comma as a soft pause—a punctuation mark that separates words, clauses, or ideas within a sentence. With few exceptions, a comma should not separate a subject from its verb…Writers are often tempted to insert a comma between a subject and verb because speakers sometimes pause at that point in a sentence. But in writing, the comma only makes the sentence seem stilted.”-Grammarly

Example of Being Rude: “My friend Cleo, is a wonderful singer.”

Example of Not Being Rude: “My friend Cleo is a wonderful singer.”

Who Has Comma Drama: You love to talk and can chat to anybody about anything. Truly, you have an extroverted side that feels energized when interacting with other people. But this means that you often write the way that you speak, treating commas like literal symbols of pauses in your speech pattern–stop that. It’s great that you’re a conversationalist, but no one can hear you on the page. When it comes to writing, you need to create rhythm and flow through punctuation, and when you’re dropping commas like loose change it’s like you’re interrupting yourself.

Alternatively, when your sentences continue without a single comma in sight, it’s like you’re rambling in one long breath. You people are hyper-caffeinated on iced coffee all day and walking around with your AirPods blasting. You never notice that you’re dance-walking to the beat with weird, flowy energy that everyone notices, but no one wants to comment and make it awkward.

Grammarly

Dangling Modifiers

What Is It: “It’s a grammatical error where the modifying word or phrase is attached to the wrong subject or where the subject is missing in a sentence. It’s fairly common and plagues even the best of writers.” -Grammarly

Example of Being Rude: “Walking into the room, the smell was overpowering.”

Example of Being Not Rude: “Walking into the room, they encountered an overpowering smell.”

Who Uses Dangling Modifiers: Literally f*cking everybody. Give yourself a break and get Grammarly.