Why It Works
Your English gaps are predictable. So is the fix.
Most TOEFL prep treats every learner the same. KotobaPro doesn't.
If your first language orders sentences differently from English, your English errors follow a predictable pattern. Subject-object-verb becomes subject-verb-object. Modifiers pile up before the noun. Because clauses reverse. Relative clauses collapse.
These aren't random mistakes. They are systematic transfer patterns — your brain applying the grammar rules it knows best to a language that works differently.
The research on this is clear. Learners who understand why they make certain errors — and who practice specifically targeting those patterns — improve faster than learners doing general practice.
Every exercise on KotobaPro is built around a specific transfer pattern. Every drill targets a moment in the test where that pattern costs points. Nothing is here for decoration.
This is not about working harder. It is about working on the right things.
Everything here is built on the published specifications. What ETS actually says about the 2026 TOEFL — what the documents specify, and where they are silent.