A Checker for Every Sentence

Grammarly’s free sentence checker allows you to write your best wherever you love to write. Check for run-on sentences, tone, clarity, and more with Grammarly.

Improve Your Sentences

Great sentences are the building blocks of great writing, but getting them just right is something that even professional writers regularly fuss over. There are many ways to muddy a sentence: complicated structure, misplaced modifiers, or confusing delivery. Two of the most common blunders involve incomplete or run-on sentences, which make writing difficult to understand. Luckily we have helpful resources to guide you toward writing crisper, cleaner, easy-to-read sentences so that your ideas don’t get lost in the shuffle.
Illustration of run-on sentences
Run-on Sentences

Recognize the traps of run-on sentences with this essential guide.
Illustration of topic sentences
Topic Sentences

Typically the first and the most important sentence in a paragraph, topic sentences aren’t only used in an introduction.
Illustration of transition sentences
Transition Sentences

Transition sentences are not optional! Bring the reader along with you every step of the way with these important idea connectors.
Illustration of sentence structure
Sentence Structure

Sentences are like houses; they need foundations. Read all about sentence structure so you have a blueprint in your head when you write.
Illustration of sentence starters
Sentence Starters

Introductions need sentences, but sometimes sentences need introductions too.
Illustration of a book all about sentences
All About Sentences

Everything you need to know about sentences (in English, at least), so you can improve your writing and dazzle your reader.

How Grammarly Can Help

Grammarlys full range of writing feedback is designed to help you make your writing the best it can be. With real-time suggestions on everything from spelling, grammar, and punctuation to tone and clarity, you can be confident that your writing presents your ideas in their best light.

Full-Sentence Rewrites

See clearer and more polished ways to say what you mean.
Full sentence rewrites examples
Example of the Grammarly product in an e-mail

Punctuation and Spelling Fixes

Be confident that your punctuation and spelling are spot-on every time.

Tone Detection

Find out how your message is likely to sound to a reader.
Gmail example of tone detection
Product example of word choice

Word Choice

Choose just the right word for the occasion.

Works Where You Write

GmailMicrosoft WordOutlookGoogle DocChromeSafariFirefoxEdgeiOSAndroid

Frequently Asked Questions

How does Grammarly’s sentence checker work?

Grammarlys algorithms analyze your sentences in real time to generate suggestions on how to improve your writing.

Where can I use Grammarly’s sentence checker?

Grammarlys sentence checker works in your browser and across all of your favorite desktop apps. You can even use it on your phone by downloading the Grammarly Keyboard.

What are run-on sentences, and how can I avoid them?

The term "run-on sentence" can describe a couple of different things. To some people, a run-on sentence is simply a very long, hard-to-follow sentence. To others, a run-on sentence is a series of clauses lacking punctuation and conjunctions between them. In either case, you can fix the problem by breaking a run-on sentence into shorter complete sentences.

What are sentence fragments, and how can I improve them?

A complete sentence needs both a subject and a verb. When one of those is missing, you end up with a sentence fragment. Its OK to use sentence fragments in casual writing (as long as you don't do it), but it's best to stick to complete sentences in more formal situations.

How can I strengthen my sentence structure?

One of the best ways to check your sentence structure is to read it out loud. If you get lost partway through or find yourself tripping over certain phrases, it's a good idea to try rewriting your sentence or breaking it into simpler ones.

What other writing feedback does Grammarly offer?

Grammarly offers a full range of writing feedback, with real-time suggestions on grammar and punctuation, clarity, vocabulary, tone, and more.

Great Writing Made Simple

Join over 30 million people who use Grammarly to improve their writing every day.