Lexical Upgrade
Replace an inaccurate word with one that fits the context.
Complex ideas, written by you.
Start with a simple sentence and work on vocabulary, structure, and logic step by step. You write every version yourself, making your English clearer and more precise.
Sign in to start. No card required.
English demo · feature details below · Practice options
Five-level practice: rewrite one sentence step by step
Work through vocabulary, structure, logic, abstraction, and integration, one skill at each level.
Build on the version you just wrote
After each level, continue from your latest sentence instead of starting again.
Focused practice: train one skill
Choose vocabulary, structure, logic, abstraction, or integration. The exercise and feedback check only the skill you select.
Sentence Restructuring
Keep the meaning, but express it through a more flexible structure.
Logical Expansion
Add a reason, effect, or condition to develop the idea.
Abstract Expression
Turn a concrete description into a more general expression.
Integrated Expression
Bring vocabulary, structure, and logic together naturally in one sentence.
Enter focused practice
Each new exercise uses 1 credit. You can submit the same exercise up to 5 times.
How Otonna evaluates your rewrite
Otonna checks the current practice goal first, then looks at whether you kept the original meaning and whether the sentence is clear and natural.
The current practice goal comes first
Five-level practice checks the current level. Focused practice checks only the skill you selected. Both require you to keep the original meaning and avoid serious grammar or expression problems.
If you disagree with a result
Mark an evaluation that does not seem fair. We use those reports to investigate judgments that are too strict, too lenient, or inconsistent.
Choose a practice plan
Try it free, practise daily, or buy an exercise pack when you need one.
Included once
Free
$0
- Exercises
- 5 exercises total
- How credits work
- Included once
- Best for
- Trying the complete method
Monthly subscription
Daily practice
$9 / month
Recommended
- Exercises
- 10 exercises a day
- How credits work
- Refills daily
- Best for
- Consistent practice
One-time purchase
30-exercise pack
$5
- Exercises
- 30 exercises total
- How credits work
- Use within 12 months
- Best for
- Occasional extra practice
Applicable taxes, if any, are calculated at Checkout.
1 credit starts 1 new exercise. Feedback and resubmissions on the same exercise do not use more credits. Five-level practice allows up to 10 submissions; focused practice allows up to 5.
Trent community offer: verify your @trentu.ca email to receive 10 free credits. Claim offer
FAQ
Frequently Asked Questions
What is Otonna?
Otonna is a guided training platform that helps English learners build accurate, varied complex sentences through progressive rewriting.
How does the 5-level training work?
You start with a simple English sentence. Each level develops one skill: precise vocabulary, structural variation, idea development, abstraction, and natural integration.
What is the difference between focused and five-level practice?
Five-level practice rewrites the same sentence one level at a time. Focused practice works on one skill you choose, allows up to 5 submissions, and does not add the result to your Library.
How are sentence credits deducted?
One credit is used when a new sentence is ready, whether you choose the full five-level method or one focused skill. If Otonna cannot generate or save it, the credit is returned automatically. Rewriting the same sentence and receiving feedback do not use more credits; the full method includes up to 10 submissions and focused practice includes up to 5.
Start with your first sentence
Practise 5 exercises freeSign in to start. No card required.