The Top Grammar Mistakes That Cost CELPIP Points
A capstone checklist of the highest-frequency errors test-takers make — and the quick fix for each. Run through this before every Writing submission.
The highest-frequency CELPIP Writing errors are missing articles, dropped third-person -s, subject-verb agreement after long phrases, tense shifts, and run-on sentences. Reserve the final 4 minutes of your writing time for a dedicated grammar pass, checking articles, -s endings, agreement, tense consistency, and sentence boundaries — most of these slips are findable, not knowledge gaps.
- What are the two most common low-level grammar mistakes?
- Missing or wrong articles (a/an/the) and dropping the third-person -s are the two most frequent low-level slips test-takers make.
- How do I fix a comma splice like "It was late, we left"?
- Add a conjunction such as "so": "It was late, so we left." Fixing run-ons and comma splices and varying your sentence length is one of the key strategies.
- What's the difference between "its" and "it's"?
- "Its" shows possession, as in "The team lost its lead," while "it's" is a contraction for "it is" — mixing them up is one of the high-frequency errors raters see.
- 1.Check articles (a/an/the) and the third-person -s — the two most common low-level slips.
- 2.Check subject-verb agreement after long phrases, and keep one consistent tense.
- 3.Fix run-ons and comma splices; vary your sentence length.
- 4.Proofread the last 3-4 minutes specifically for these — most errors are findable, not unknown.
The high-frequency error list
These are the mistakes raters see most often. Knowing them turns proofreading into a quick checklist.
1. Missing or wrong articles
✗ "I am student. I went to the home." → ✓ "I am a student. I went home."
2. Dropped third-person -s
✗ "He work hard." → ✓ "He works hard."
3. Subject–verb agreement after a long phrase
✗ "The list of names are long." → ✓ "The list of names is long."
4. Tense shifting
✗ "Yesterday I go out and bought food." → ✓ "Yesterday I went out and bought food."
5. Run-ons / comma splices
✗ "It was late, we left." → ✓ "It was late, so we left."
6. Preposition errors
✗ "It depends of you. I will arrive in Monday." → ✓ "It depends on you. I will arrive on Monday."
7. Uncountable plurals
✗ "many informations, some advices" → ✓ "much information, some advice"
8. its vs. it's
✗ "The team lost it's lead." → ✓ "The team lost its lead."
9. Double comparatives
✗ "more easier" → ✓ "easier"
10. Wrong word form
✗ "She is a very success person." → ✓ "She is a very successful person."
Your 4-minute proofreading routine
After writing, do two passes:
- Content pass — did I answer every part of the prompt?
- Grammar pass — run this checklist: articles, -s endings, agreement, tense consistency, sentence boundaries.
Most of these errors are not gaps in knowledge — they are slips you can catch. Building the habit of a focused final check is one of the highest-value things you can do for your Writing score.
Check yourself
A quick self-check on this lesson — pick an answer, then see the explanation. Not graded.
Grow your Grammar vocabulary
The right words lift your score. Study task-specific CELPIP word lists with definitions, examples and exam tips.
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