LingoLeap Research
TOEFL research from real practice data
Every day, thousands of learners complete TOEFL speaking and writing practice on LingoLeap and receive AI scores. We turn that anonymised, aggregated data into descriptive studies that answer questions a small sample cannot — which sounds are hardest, where sentences start to break, how first language shapes pronunciation. Every study publishes aggregates only: no recordings, transcripts, or identities.
Listen and Repeat · Pronunciation
Which English sounds are hardest for Chinese TOEFL learners?
Chinese- and English-interface learners score almost identically on every sound — except /θ/, the single hardest sound for Chinese-first-language learners at 63.5/100.
/θ/ 63.5
hardest sound, Chinese L1
Listen and Repeat · Speaking
What 152,218 Listen and Repeat attempts taught us
A descriptive study of sentence length, pauses, word endings, and phoneme-level pronunciation across 23,390 real TOEFL 2026 practice sessions.
152,218
scored sentence attempts
How we work
- Data comes from real, voluntary TOEFL practice on LingoLeap, anonymised and aggregated.
- Pronunciation is scored by automatic speech assessment; sentence scores are LingoLeap AI scores, not official ETS results.
- We publish aggregate statistics and charts only — never recordings, transcripts, user IDs, or individual responses.
- Studies are observational and descriptive: we report denominators and differences, not causal effects.
Want to put the research to work?
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