How to Memorize Vocabulary in a New Language
This guide gives you a plan for learning vocabulary in a new language: which words to pick, how to write the cards, when to review them and what to do with the words that will not stay. By the end you can build your first batch of cards.
Most steps below are practical advice built on two general findings that have verified sources. In one meta-analysis, recall tests produced larger testing benefits than recognition tests, and in another the best gap between study sessions grew as the final test got further away. The studies we cite did not test each step separately, for example writing cards in both directions, and results vary from person to person.
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Choose a small batch of words you will meet again
Start with words from material you are really using, such as the chapter you are reading or the conversation you want to have next week. A word you meet again soon gets extra practice outside your cards.
Keep each batch small. Say you add 10 new words per session (an illustration, not a rule). That is enough to see progress and few enough to write each card with care. If your review pile grows faster than you can clear it, add fewer words rather than more hours.
Write cards that run in both directions
A card shows a prompt on the front and the answer on the back. Recognition means you see the answer and think "yes, that looks right." Recall means you pull the answer out of memory with nothing in front of you.
A meta-analysis comparing testing with restudying found that initial recall tests produced larger testing benefits than recognition tests (Rowland, 2014). It did not look at vocabulary cards in particular, so our two-way advice is practical advice resting on that general finding, not a tested recipe.
| Card format | Front | Back | What it trains |
|---|---|---|---|
| Word to meaning | la llave | key | Understanding the word when you read or hear it |
| Meaning to word | key (what opens a door) | la llave | Producing the word when you speak or write |
| Gap sentence | Abro la puerta con la ___. | llave (I open the door with the key) | Using the word inside a sentence |
| Word in a phrase | la llave de la casa | the house key | Seeing which words travel together |
| Picture to word | A photo of a key | la llave | Linking the word to the thing without translating |
Begin with meaning to word for words you need to say or write, and word to meaning for words you only need to understand. Add the gap sentence once the word stands on its own. More card rules are in how to write flashcards that work.
Space your reviews across days and weeks
Spacing means reviewing after a gap instead of all at once. A meta-analysis pooled 839 assessments from 317 experiments on spaced practice in verbal recall tasks and found that the best gap between study sessions grew as the time until the final test grew (Cepeda et al., 2006). Those tasks were mostly word lists and facts studied in laboratories.
A long study followed four people for 9 years as they learned and relearned 300 English and foreign-language word pairs. Longer gaps between relearning sessions slowed learning slightly, but they led to substantially higher retention in later tests (Bahrick et al., 1993). Four people and gaps of weeks or months are far from a school schedule, so take the direction, not the numbers.
In Practice, a card moves through five boxes with waits of 1, 2, 4, 8 and 16 days. That is a simple model inspired by the Leitner system, not a claim about the best schedule. If you want the basics first, read what spaced repetition is.
Rescue stubborn words and run a weekly check
Some words slide off because they sound like nothing you know. The keyword method gives them a hook in two steps: find an English word that sounds like the foreign word, then picture that word interacting with the meaning (Atkinson, 1975). In a Russian-vocabulary experiment, the keyword group recalled more words than the control group on a comprehensive test and on a delayed test six weeks later.
A later major review judged the keyword mnemonic to be limited: it appeared to help for a limited number of materials and short retention intervals (Dunlosky et al., 2013). The keyword method guide walks through both steps.
The weekly check
- Pick a random sample from earlier batches, for example 20 words (an illustration).
- Answer meaning to word first, then word to meaning, with no notes.
- Mark every miss and rewrite its card with a better sentence or a keyword.
- Note which direction was harder and add more cards of that type.
Words built from Latin and Greek roots can be split into parts, as the science terms guide shows. If you will speak in your new language, see how to memorize a speech, and for phone numbers and dates, see numbers and sequences.
Common mistakes
- Adding more new words than you can review. Cap new words at a number you can review comfortably tomorrow. If reviews pile up, pause new words until they are cleared.
- Writing only word-to-meaning cards. Add meaning-to-word cards for the words you need to say or write, so you practice producing them.
- Using the keyword method for every word. Save it for words that keep failing. A card with a short example sentence is enough for most words.
- Counting a word as learned after one correct answer. Check it again after a wait, with no notes. A word that comes back days later is a better sign than one that comes back a minute later.
Frequently asked questions
How many new words should I learn per day?
The studies we cite give no number for this. Add only as many words as you can review comfortably over the next few days. Ten per session is only an illustration; lower it if reviews pile up.
Do I need a card in each direction for every word?
No. Write meaning-to-word cards for words you need to say or write, and word-to-meaning cards for words you only need to understand. You can add the second direction later for words you keep missing. This is practical advice, not a finding from the studies we cite.
Does the keyword method work for every word?
No. Atkinson's experiments tested vocabulary lists, and a major review later judged it limited: it appeared to help for a limited number of materials and short retention intervals. Try it on a few stubborn words and drop it if it feels forced.
How do I know a word is learned?
Look for unaided recall after a wait: you answer correctly days later without notes. In Practice a card counts as mastered after a right answer while it is already in box 5. That is the tool's own rule, not a scientific standard.
Sources
We opened each source below before citing it. See Methodology and Sources for how we check them.
- Rowland, C. A. (2014). The effect of testing versus restudy on retention: A meta-analytic review of the testing effect. Psychological Bulletin, 140(6), 1432-1463. Open the source
- Cepeda, N. J., Pashler, H., Vul, E., Wixted, J. T., & Rohrer, D. (2006). Distributed practice in verbal recall tasks: A review and quantitative synthesis. Psychological Bulletin, 132(3), 354-380. Open the source
- Bahrick, H. P., Bahrick, L. E., Bahrick, A. S., & Bahrick, P. E. (1993). Maintenance of Foreign Language Vocabulary and the Spacing Effect. Psychological Science, 4(5), 316-321. Open the source
- Atkinson, R. C. (1975). Mnemotechnics in second-language learning. American Psychologist, 30(8), 821-828. Open the source
- Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J., & Willingham, D. T. (2013). Improving Students' Learning With Effective Learning Techniques: Promising Directions From Cognitive and Educational Psychology. Psychological Science in the Public Interest, 14(1), 4-58. Open the source
This guide is general study help, not medical or professional advice. It was last reviewed on November 12, 2026. Spot a mistake? Tell us here.