“Is this sentence correct?” If you have ever written a sentence, read it back, and felt a small doubt in your stomach — welcome. You are in good company.
Every week, my students ask me this exact question. Sometimes the sentence is fine. Sometimes one small word is wrong. I always tell them the same thing: asking the question is the real skill. It means your brain is already learning.
In this guide, I will show you five free ways to check your own grammar — no paid apps, no teacher needed — plus real before-and-after examples of the mistakes I see most in my classroom. By the end, you will answer “is this sentence correct?” for yourself, with confidence.
Why Every Learner Asks “Is This Sentence Correct?”
Doubting your sentences is not a weakness. It is a sign you care about writing well.
Even confident writers feel unsure
A “native speaker” is someone who grew up speaking English at home — and even they check their grammar. They pause before important emails and re-read sentences three times. If lifelong English speakers still ask “is this correct?”, never feel ashamed of asking it.
Guessing keeps you stuck
When you guess, you practise the mistake — and your brain remembers what you repeat. That is why learning to check a sentence matters more than memorising grammar rules. Every check turns a sentence into a small lesson.
How to Check If Your Sentence Is Correct: 5 Free Methods
You do not need expensive software. Start with these five methods. They cost nothing, and they work.
Method 1: Read it out loud
Read your sentence aloud — slowly. Your ear catches what your eye misses. If you stumble over a word or the sentence sounds strange, something is probably wrong; correct sentences usually sound smooth. Try it with something you wrote today — the bumpy part is where the mistake is hiding.
Method 2: Find the subject and the verb
Every complete sentence has two main parts:
- The subject — who or what the sentence is about.
- The verb — the action word, or a “being” word like is, are, was.
Example: “My sister cooks delicious food.” Subject: “my sister”. Verb: “cooks”.
Here is the golden rule: the verb must match the subject — “he goes” but “they go”. This is called subject-verb agreement: singular subjects take singular verbs, plural subjects take plural verbs. When a sentence feels wrong, check this match first — half of all mistakes live right here.
Method 3: Ask three quick questions
Run every doubtful sentence through these three questions:
- Who is doing what? Can you point to the subject and the verb? If you cannot find them, the sentence may be incomplete.
- Does the verb match the subject? “He go” should be “he goes”. “They was” should be “they were”.
- Is the thought complete? Read it once more. Does it feel finished, or is your brain waiting for more? “Because I was tired” is not complete. “I slept early because I was tired” is complete.
If your sentence passes all three, it is very likely correct.
Method 4: Compare with a sentence you trust
Find a sentence with the same pattern from a book or a teacher’s example, and put it next to yours. You trust: “She has lived here for five years.” Yours: “He has worked there since three years.” Lining them up shows the difference — for a period, since a point in time. So yours becomes: “He has worked there for three years.” Comparison is one of the fastest ways to learn.
Method 5: Run it through a free grammar checker
When your own eyes are tired, let a free tool take a look — I list my favourites below. Use them as a second opinion, not a replacement for your judgement.
“Is This Sentence Correct?” — 6 Mistakes My Students Make Most
Here are the mistakes I correct most often in my classes, shown before and after. Study each pair. I promise you will start spotting these in your own writing.
1. The verb does not match the subject
Wrong: “He go to office every day.” — Right: “He goes to the office every day.”
Why: “He” needs “goes”, not “go”. And we say “the office” — places like this need “the”.
2. “A” instead of “an”
Wrong: “She is a honest teacher.” — Right: “She is an honest teacher.”
Why: Use “an” before a vowel sound. “Honest” starts with an “o” sound, so it takes “an”. (The letter H is silent here!)
3. Wrong tense with a finished time
Wrong: “I have seen her yesterday.” — Right: “I saw her yesterday.”
Why: “Yesterday” is finished time. Finished time always takes the simple past — “saw”, not “have seen”.
4. Missing article before a job
Wrong: “She is teacher.” — Right: “She is a teacher.”
Why: In English, jobs and roles need a/an: a teacher, an engineer, a doctor. This is the mistake I see most from Urdu and Punjabi speakers, because our languages do not use articles the same way.
5. “Since” instead of “for”
Wrong: “I am waiting since two hours.” — Right: “I have been waiting for two hours.”
Why: “Since” is for a point in time (“since morning”); “for” is for a period (“for two hours”). An action that started in the past and continues now needs “have been waiting”.
6. “It’s” instead of “its”
Wrong: “The dog wagged it’s tail.” — Right: “The dog wagged its tail.”
Why: “It’s” always means “it is”. “Its” (no apostrophe) means “belonging to it”. If you can replace the word with “it is” and the sentence still works, use “it’s”. Otherwise, use “its”.
Once your sentences are correct, the next step is making them fuller and richer. Here is how to make a paragraph longer: https://sadiazeeshan.com/how-to-make-paragraph-longer/ — once your sentences are solid.
Free Tools That Answer “Is This Sentence Correct?”
These tools are free and beginner-friendly. I recommend them to my students all the time:
- Grammarly (free version) — checks your writing as you type, in your browser or in documents. The free version catches most basic mistakes.
- LanguageTool — a free online checker that works well and respects your privacy better than most.
- Google Docs — if you write in Google Docs, its built-in spelling and grammar check underlines mistakes for free. Right-click any underline to see the suggestion.
- QuillBot grammar checker — paste your sentence into their free online tool for a quick check.
One honest warning: tools catch mistakes but do not teach you. Each time a tool fixes something, ask “Why was it wrong?” — that question turns a correction into a lasting lesson. And never accept every suggestion blindly; tools sometimes misunderstand what you meant.
Frequently Asked Questions
How can I check if my sentence is grammatically correct for free?
Read it aloud, run the three quick questions (who is doing what? does the verb match? is it complete?), then confirm with a free tool like Grammarly, LanguageTool, or Google Docs. Your own check plus a tool’s check catches almost everything.
What is the most common grammar mistake beginners make?
Subject-verb agreement — writing “he go” instead of “he goes”, or “they was” instead of “they were”. The second most common is dropping articles: writing “she is teacher” instead of “she is a teacher”. Master these two and your writing will improve immediately.
Is it okay to use AI grammar checkers for my homework?
As your teacher, here is my honest answer: use them to learn, not to hide. It is fine to run your homework through a checker and study every correction. It is not fine to let the tool write for you and learn nothing. Teachers can usually tell the difference — and more importantly, exams do not allow grammar checkers. The goal is a stronger you, not a stronger tool.
How long will it take before I stop making grammar mistakes?
Here is the truth nobody tells beginners: nobody fully stops. Even professional writers and native speakers make mistakes and check their work. So do not aim for perfection — aim for fewer mistakes and for catching your own. Every month you practise, the doubtful moments get shorter. That is real progress.
Keep Going — You Are Closer Than You Think
Look at what you can do now. You can read a sentence aloud and hear the bumpy parts. You can find the subject and the verb. You can ask three quick questions. You can spot the six most common mistakes. That is not small — that is the foundation of good English.
Next time that little doubt appears — “is this sentence correct?” — smile. Your learning brain is working. Check it, fix it, move on. Every corrected sentence makes the next one easier.
Want to see correct sentences working inside real articles? Explore my blog post examples: https://sadiazeeshan.com/blog-post-examples/ — next, and keep practising a little every day. I am cheering for you.