Acquire another language
Transferable systems for adults learning any language: perception, vocabulary, grammar, interaction, and durable practice.
Topic map
Starting sequence
Start with the first article, then choose by goal—not by whatever is newest.
A rigorous adult language-learning system built around target situations, balanced practice, Mandarin transfer diagnosis, and evidence from real use.
Turn vocabulary recognition into usable language through multidimensional word knowledge, retrieval, spacing, chunks, and Mandarin transfer tests.
Diagnose signal, perception, segmentation, production, and intelligibility with worked Mandarin, Spanish, Japanese, and Arabic examples.
Use AI for bounded language practice while protecting agency, privacy, linguistic variety, verification, and transfer to uncontrolled human communication.
Estimate language-learning time through target performances, starting conditions, opportunity quality, uncertainty ranges, and repeated real-world evidence.
Understand what CEFR A1–C2 descriptors mean, why real profiles are uneven, how to build a Spanish can-do card, and what a level cannot diagnose.
A claim-by-claim examination of bilingual cognition, executive-control controversy, language-use context, sociolinguistic confounding, and real adaptation.
Learn what comprehensible input contributes, why understood messages do not automatically become usable language, and how to run an input-to-use Spanish cycle.
Diagnose why language recognition outpaces speaking, distinguish lexical access from planning and anxiety, and run a Spanish recognition-to-production bridge.
Diagnose fast-speech difficulty through segmentation, reduction, lexical access, prediction, and a Mexico City Spanish ten-second listening autopsy.
Separate accent, intelligibility, comprehensibility, and fluency; diagnose a Japanese mora-length consequence; and set pronunciation goals without erasure.
Move grammar from explicit explanation to timely use through cue detection, constrained choice, meaningful retrieval, feedback, fluency, and Japanese transfer tests.
Replace one magical vocabulary target with a purpose-specific model of frequency, lexical coverage, depth, formulaic sequences, and productive use.
Diagnose freezing as the interaction of retrieval, formulation, attention, anxiety, task demands, and repair—then train fluency without demanding speed.
Match correction to the task, error, learner, and moment so feedback improves intelligibility, accuracy, and independence without destroying interaction.
Build second-language reading fluency by combining lexical coverage, automatic decoding, extensive volume, strategic close reading, and retesting.
Build direct written production from intentions, target-language patterns, drafting, corpus-informed revision, feedback, and delayed independent writing.
Decide whether to study two languages concurrently by testing goals, weekly opportunity, maintenance load, cross-language transfer, and confusion risks.
Use crosslinguistic influence as a source of hypotheses: exploit verified similarities, contrast costly differences, and test transfer in real tasks.
Distinguish measurement ceilings, stable routines, narrow input, avoidance, weak feedback, and persistent interlanguage before redesigning practice.
A scenario analysis of how ambient translation can expand access while redistributing power through language quality, cultural fit, data, and verification.
A reproducible 160-string test of NFC, NFKC, search-key equality, width variants, combining marks, compatibility forms, and directional controls.