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What should be on the front and back of a vocabulary flashcard, and is audio needed for vocabulary or example sentences?

Evidence-based answer · Last updated · How it’s made

The short answer

Research points to a fairly clear "best-practice" flashcard design: the front should show just the target word (ideally in a retrieval-practice format, meaning you have to produce the answer, not just recognize it), and the back should give a translation into your own language plus a picture — with an audio clip of pronunciation as a helpful but secondary extra. Audio and pictures for the vocabulary word itself do seem to help; audio or images baked into example sentences are less studied and one related finding suggests images can even backfire if they give the answer away too easily.

Answered for language learning in general. No specific language was set for this question, so the findings are drawn from general second-language research rather than one language’s literature.

Retrieval practice format matters more than layout

The single biggest lever in flashcard design isn't what's printed on the card, it's whether the card format forces you to actively recall the answer before seeing it, rather than just re-reading a fact you've already been shown. Cards used this way outperform simply re-studying the same information.7,14,15,16

In plain terms

'Retrieval practice' means testing yourself on a word before checking the answer, instead of just re-reading the word and its meaning together. Studies find this active recall process is what actually builds long-term memory, more so than any particular combination of text, pictures or sound on the card.

Translation is the most valued back-of-card content

When learners were asked which flashcard element helped them most, a native-language translation and a picture came out on top, while a foreign-language definition (a definition written in the language being learned) was rated as the least helpful component.6

Foreign-language definitions underperform translations

Definitions written in the target language were consistently rated less helpful than translations into the learner's own language, especially at the point when a learner is still linking a new word's form to its meaning.6

Example

For a Thai speaker learning English, this suggests that on the back of a card, writing the Thai translation of a word (แมว for 'cat') is likely more useful early on than writing an English-only definition like 'a small domesticated feline.'

Pictures help, but timing and clarity matter

Adding a picture to the vocabulary card generally improves learning of concrete, picturable words. However, if the picture makes the answer too obvious during the actual recall attempt (i.e., you see the picture before you've tried to remember the word), it can backfire and weaken long-term memory, even though learners feel they're learning more.2,5,8,12

Example

Seeing a photo of a dog right next to the blank you're supposed to fill in with the foreign word for 'dog' lets you guess without really retrieving it from memory, so you remember it less well later, compared to a card where the picture only appears after you've tried to answer.

Audio on the vocabulary side has mixed but generally positive support

Adding audio pronunciation to a vocabulary card, especially alongside a picture and text, tends to improve learning and retention compared with text-only cards. However, when forced to choose, learners themselves rank pronunciation audio below translation and images in perceived helpfulness.3,4,5,6

Combining several supports beats a single one

Cards or lessons that combine multiple supportive elements, such as a definition plus extra word information plus a video, produced better vocabulary learning and retention than any single element alone (like a bare definition).4

Context-rich example sentences may boost engagement

Adding a meaningful, relatable example sentence to a card, not just the isolated word and its translation, was associated with stronger engagement and vocabulary gains for low-proficiency learners in one program, particularly when the sentences were humorous or tied to things students already knew.10

Example

A card for a difficult English word might use an example sentence referencing a popular TV show the students all watch, rather than a generic textbook sentence.

Word concreteness changes what helps

Abstract words (like 'freedom' or 'opportunity') are harder to learn from flashcards than concrete, picturable words (like 'table' or 'dog'), and immediately after study a picture-based card helps more, though this advantage evens out over time.8

Producing a word helps more than just recognizing it

Practicing by producing the foreign word yourself (writing the English word when shown the Thai translation) builds stronger and more well-rounded word knowledge than only practicing recognition (being shown the English word and picking its meaning).9,13

In plain terms

'Receptive' knowledge means being able to recognize or understand a word when you see or hear it; 'productive' knowledge means being able to come up with the word yourself when you need it, such as when speaking or writing.

Example

Testing yourself by covering the English side and trying to say or write the word from the Thai translation, rather than just reading English word and Thai meaning together, builds more complete knowledge of that word.

Paper vs digital cards both work, ready-made vs self-made mixed

Both paper and digital (app-based) flashcards produce real vocabulary gains, and one large research review found paper cards showed larger effects in more studies than digital ones, and ready-made card sets showed larger effects than self-made ones, though the evidence isn't fully consistent across studies.1,9,11

What to do with this

  • Based on the sources, a well-designed vocabulary flashcard for a Thai learner of English (or any second language) should have: Front — just the target word (or the Thai translation, alternating direction is fine) with nothing that gives away the answer, so you're forced to actively try to recall it.
  • Back — the Thai translation (this was consistently rated more useful than a foreign-language definition), a small picture for concrete nouns, and an audio clip of the pronunciation.
  • Skip or minimize target-language-only definitions, since learners in the cited research found these the least helpful element and they can clutter the card.
  • If you include an example sentence, make it something meaningful or memorable rather than a generic textbook line, as this seems to support engagement, especially for lower-level learners.
  • Audio isn't strictly required for vocabulary but seems to add real value, particularly combined with a picture and text; audio on example sentences specifically wasn't well tested in these sources, so it's a reasonable but less evidence-backed extra.
  • Whatever combination you use, prioritize actually testing yourself (trying to recall or produce the word) over passively re-reading the card, and review cards using spaced repetition rather than cramming everything in one sitting.

Now pick something to do it with

Each of these opens an overview of the apps, courses and immersion material worth a look for that — filtered to exactly what the advice above points you at:

FlashcardsSpaced repetition (SRS)Sentence miningResource selection
Or see the full resource list

Worth knowing

  • Most of these studies were conducted with English learners whose native language was Chinese, Japanese, Polish, Indonesian, Turkish, or Korean, not Thai, so any claims framed around Thai are extrapolations from general second-language findings rather than Thai-specific data; only one source even had a small number of Thai speakers among mixed nationalities, and it didn't analyze them separately.
  • Findings on example-sentence audio specifically are thin, most sources focus on audio for the standalone word rather than for full sentences.
  • Some results conflict (one review found paper cards outperforming digital in more studies, while a controlled trial found digital flashcards beating paper cards), and one flashcard-intervention study found no significant difference between flashcard types at all, so design choices likely matter less than consistent, spaced, active-recall practice.

Want a deeper literature dive?

There’s enough published research here to go wider than the usual pass. Available on the Pro plan.

See plans

  1. [1]Yuanying Lei, Barry Lee Reynolds. Learning English vocabulary from word cards: A research synthesis. Frontiers in Psychology 2022. doi.org/10.3389/fpsyg.2022.984211
  2. [2]van den Broek, Gesa S. E., van Gog, Tamara, Jansen, Evelien, Pleijsant, Mirja, Kester, Liesbeth. Multimedia Effects during Retrieval Practice: Images That Reveal the Answer Reduce Vocabulary Learning. Journal of Educational Psychology 2021. doi.org/10.1037/edu0000499
  3. [3]Nakata, Tatsuya. Computer-Assisted Second Language Vocabulary Learning in a Paired-Associate Paradigm: A Critical Investigation of Flashcard Software. Computer Assisted Language Learning 2011. http://www.informaworld.com/openurl?genre=article&id=doi:10.1080/09588221.2010.520675
  4. [4]M. Teng. The effectiveness of multimedia input on vocabulary learning and retention. Innovation in Language Learning and Teaching 2022. doi.org/10.1080/17501229.2022.2131791
  5. [5]Joshua Hicks, Rina Marnita, Oktavianus Oktavianus. Comparing the effectiveness of multimodal vs monomodal digital flashcards for L2 vocabulary learning. Studies in English language and education 2025. doi.org/10.24815/siele.v12i3.39630
  6. [6]Kaplan-Rakowski, Regina, Loranc-Paszylk, Barbara. Students' Views on the Helpfulness of Multimedia Components of Digital Flashcards in Mobile-Assisted Vocabulary Learning. Research-publishing.net 2017. https://eric.ed.gov/?id=ED578272
  7. [7]N. Karatas, Oya Özemir, Jarrett Lovelett, Bora Demir, Kemal Erkol, J. Veríssimo, G. Erçetin, M. Ullman. Improving second language vocabulary learning and retention by leveraging memory enhancement techniques: A multidomain pedagogical approach. Language Teaching Research 2021. doi.org/10.1177/13621688211053525
  8. [8]Anne Rimrott. Computer-assisted vocabulary learning: multimedia annotations, word concreteness, and individualized instruction. Summit (Simon Fraser University) 2010. http://summit.sfu.ca/item/11876
  9. [9]Mahtab Mohammadi, Mohammadreza Valızadeh, Parisa Zohdi Jalal, Ismail Xodabande. University students’ academic vocabulary development through mobile-assisted learning: Exploring the impacts on receptive and productive knowledge. Heliyon 2024. doi.org/10.1016/j.heliyon.2024.e28103
  10. [10]J. Richard. A trial study of context-rich NGSL word cards for lower-proficiency learners. Vocabulary Learning and Instruction 2026. doi.org/10.29140/vli.2026.103526
  11. [11]Nirmani Dayapathirana, Madhara Prabodini, Sewwandi Poornima. Quantitative Action Research on Enhancing French Vocabulary Acquisition: The Efficacy of Flashcard-Based Learning among Undergraduates. Journal of Teaching and Learning 2025. https://eric.ed.gov/?id=EJ1490348
  12. [12]Khalid Al-Seghayer. The effect of multimedia annotation modes on l2 vocabulary acquisition: A comparative study. Language learning & technology 2001. doi.org/10.64152/10125/25117
  13. [13]Stuart Webb. The Effects of Receptive and Productive Learning of Word Pairs on Vocabulary Knowledge. RELC Journal 2009. doi.org/10.1177/0033688209343854
  14. [14]Estiningtyas Sholikhah, Fitrilya Anjarsari. The Metronome of Memory: Spaced Flip-Card Practice for Indonesian EFL Learners. JIMU:Jurnal Ilmiah Multidisipliner 2025. doi.org/10.70294/jimu.v3i03.1187
  15. [15]Shan Huang, Hong-Wen Cao, Jiayi Wang, Shutong Liu. The Moderating Role of Learning Rounds: Effects on Retrieval Practice and Context Dependence in Digital Flashcard Foreign Language Vocabulary Learning. Behavioral Sciences 2025. doi.org/10.3390/bs15111540
  16. [16]Ryo Maie, Gaia Oikawa, Ying Chen, Takumi Uchihara. Cumulative Testing for <scp>L2</scp> Vocabulary Learning: The Impact of Retrieval Practice and Proficiency. TESOL Quarterly 2025. doi.org/10.1002/tesq.3391