Dia, Blog
Research-backed language learning
Evidence-based articles for adults learning to speak a new language.
- 9 min read
DELF B1 Speaking Exam (Production Orale): What Each Part Asks and How to Practice Out Loud
What the three parts of the DELF B1 production orale ask you to do and how the 25 points are given, based on France Éducation international's sample papers and grid, and how to rehearse each part out loud with Dia. Includes a short note on the DELF A2 and B2 orals.
Speaking · Intermediate
- 9 min read
DELE A2 and B1 Speaking Test: What Each Task Asks and How to Practice Out Loud
What the expresión e interacción orales part of the DELE A2 and B1 asks you to do, based on the Instituto Cervantes' exam guides and model exams, with a short note on B2, and how to rehearse each task out loud with Dia.
Speaking · Beginners · Intermediate
- 9 min read
telc B1, ÖIF and Goethe B1 Speaking Exams: What Each Part Asks and How to Practice Out Loud
What the oral parts of telc Deutsch B1, the ÖIF Integrationsprüfung (A2 and B1) and the Goethe-Zertifikat B1 ask you to do, based on the official model tests, and how to rehearse each part out loud with Dia in Standard, Austrian or Swiss German.
Speaking · Intermediate
- 6 min read
Dia vs Talkpal (2026): Price, Languages and Which AI Tutor to Pick
Talkpal offers 130+ languages and many practice modes. Dia focuses on one conversation that corrects you, remembers you and speaks the regional variety you choose. Prices and features as of November 2026, from Dia's founder, including when Talkpal is the better pick.
Speaking · Methodology
- 6 min read
Dia vs Praktika (2026): Price, Languages and Which AI Tutor to Pick
Praktika pairs AI avatar tutors with a lesson library in 13 languages. Dia is open conversation in 28 languages with regional variants, on the web and in apps. Prices and features as of November 2026, from Dia's founder, including when Praktika is the better pick.
Speaking · Methodology
- 6 min read
Dia vs Speak (2026): Price, Languages and Which AI Tutor to Pick
Speak teaches six languages to English speakers through guided lessons. Dia is open conversation in 28 languages, German included. Prices and features as of November 2026, from Dia's founder, including when Speak is the better pick.
Speaking · Methodology
- 4 min read
Beat the Forgetting Curve: Why Recall Beats Re-Reading
Re-reading trains recognition. Recalling trains memory, and in Karpicke and Roediger's studies it improved retention by about 50%.
Memory · Methodology · Beginners
- 4 min read
The Silent Period in Language Learning: When to Start Speaking
Many learners listen for weeks before they speak, and that silent phase is useful rehearsal. After about four weeks without trying to speak, it turns into avoidance.
Beginners · Methodology · Research
- 5 min read
Comprehensible Input: Why Listening Alone Won't Make You Fluent
Hours of input make you a good listener. Speaking fluently also takes output and feedback, as Long's interaction research showed.
Methodology · Research · Fluency
- 5 min read
Code-Switching and the Bilingual Brain: Why Mixing Languages Helps
Fluent bilinguals mix languages on purpose. Switching between languages every day trains cognitive control.
Neuroscience · Culture · Research
- 7 min read
Best AI Language Tutors in 2026: ChatGPT, Duolingo, Human Tutors and Dia Compared
ChatGPT, Duolingo, human tutors and dedicated AI tutors each solve a different problem. Written by Dia's founder, including where Dia is not the best choice: exam prep and C1+ polish.
Research · Methodology · Speaking
- 7 min read
The Shadowing Technique: A Complete Guide (With a 2-Week Plan)
Shadowing means repeating speech while you still hear it, with no pause to translate. The method, the research, common mistakes and a 14-day plan with a before and after recording.
Pronunciation · Speaking · Methodology
- 6 min read
Daily Speaking Practice: Retention Data From 9,000 Learners
Our retention data from 9,000 learners, including the weak numbers. Learners who went further on day one, practiced by voice or checked in daily kept practicing far more often.
Research · Speaking · Methodology
- 6 min read
What CEFR Level Are You? A 10-Minute Self-Assessment
Most learners rate themselves a level too high. Three checks (30-second turns, live disagreement, native-to-native listening) place you in about ten minutes.
Methodology · Beginners · Intermediate
- 6 min read
Why You Understand a Language But Can't Speak It (and the 4-Week Fix)
Understanding relies on recognition and speaking on fast retrieval, and each is trained separately. A 4-week plan to activate the vocabulary you already know.
Speaking · Intermediate · Fluency
- 7 min read
Is Talking to an AI Good Language Practice? What the Research Says
The interaction loop that drives acquisition works with an AI partner, and the research on speaking anxiety favors it. The post also covers five places where AI practice falls short.
Research · Speaking · Methodology
- 6 min read
Mexican Spanish vs. Spain Spanish: Which Should You Learn First?
Spain and Latin America differ in pronunciation (distinción vs. seseo), in vosotros vs. ustedes and in a handful of words like coche and carro. Pick the one for where you will use it.
Culture · Beginners · Speaking
- 6 min read
How Long Does It Take to Learn Spanish? Hours by Level
The FSI estimates 600–750 hours to professional proficiency, and conversational B1 takes about 350–400. A table shows what that means at 15, 30 or 60 minutes a day.
Beginners · Methodology · Research
- 7 min read
After Duolingo: A 90-Day Plan to Start Speaking
Duolingo builds recognition and a daily habit but little speaking practice. This post compares the next steps and gives a 90-day plan for turning what you know into conversation.
Methodology · Intermediate · Speaking
- 6 min read
How to Practice Speaking a Language Alone: 5 Drills
Shadowing, self-recording and timed monologues build speaking skill on your own. Unpredictable questions and repair after a misunderstanding still need a partner.
Speaking · Methodology · Fluency
- 5 min read
Conversational Fluency vs Academic Fluency: Which One You Need
BICS, everyday conversational fluency, takes 6 to 24 months of immersion. CALP, academic fluency, takes 5 to 7 years. Most learners need BICS first.
Fluency · Methodology · Culture
- 5 min read
Your Native Language Helps More Than It Hurts
Most of the worry about L1 interference is outdated. Your native language supports early learning, and real interference is limited to sounds, false friends and idioms.
Research · Methodology · Beginners
- 5 min read
Why Native Speakers Sound 'Too Fast' (and How to Catch Up)
Native speakers are not faster than textbook audio. They shorten and link words in ways textbooks rarely record.
Speaking · Fluency · Pronunciation
- 5 min read
Sleep Is When Languages Stick: The Neuroscience of Consolidation
New words and grammar are consolidated while you sleep. Reviewing before bed and practicing a few minutes every day make the most of it.
Neuroscience · Memory · Research
- 5 min read
Bilingualism and Executive Function: What the Studies Find
Bilinguals are not smarter on average. Many studies find benefits for attention and task-switching and a later onset of dementia symptoms.
Neuroscience · Research · Culture
- 4 min read
Your First 1,000 Words Cover 75% of Real Speech
Learn words in order of frequency rather than by topic. The 1,000 most common words cover about 75% of everyday speech.
Memory · Beginners · Methodology
- 5 min read
Pronunciation Is a Motor Skill: How to Train It
Accent comes from tongue, lips, jaw and breath working together within milliseconds. Minimal-pair drills with fast feedback train that pattern.
Pronunciation · Neuroscience · Speaking
- 5 min read
The Output Hypothesis: Why Speaking Beats Listening for Fluency
Listening builds understanding. Swain's output hypothesis says you learn to speak by having to produce the language yourself.
Speaking · Methodology · Fluency
- 5 min read
Spaced Repetition + Conversation: Why Both Beat Either Alone
Flashcards train recognition and conversation trains retrieval. Learners who combine them keep more vocabulary than with either method alone.
Memory · Methodology · Research
- 7 min read
Why You Plateau at B1 (and the 30-Day Plan to Break Out)
Flashcards get most learners to B1 and stall there. Reading in your own field and conversations with 30-second turns move you toward B2 and C1.
Intermediate · Methodology · Fluency
- 6 min read
Adults Can Reach Fluency: The Critical Period Hypothesis Is a Myth
MIT's 670,000-person study found that grammar-learning ability holds steady until about 17.4 and declines slowly after that. Adults who start later still become fluent with enough practice.
Neuroscience · Research · Beginners