The 80/20 Principle in Learning Vocabulary

Learn New Words Efficiently 

The world is filled with asymmetry and nonlinearity. One unit of input rarely equates to one unit of output. This is also known as 80/20 “Pareto” principle, named after the 19th-century Italian economist Vilfredo Pareto who observed this unequal relationship when studying peas in his garden. When he harvested the peas, he noticed that not all pods produced edible full-sizes peas. Some pods didn’t have any peas, and others dried up. He estimated that 80% of the peas were produced by 20% of the pods. This epiphany led him to study nonlinearity. After crunching the numbers, he saw the same asymmetric distribution in land ownership: 80% of the land was owned by 20% of the Italian population.

Students who acquire vocabulary by prioritizing word frequency and word relevance will get the best bang for their buck, the highest return on their learning investment




The 80/20 principle is a statistical observation that describes numerous occurrences across different fields. Many situations are modeled as power law distributions because small differences compound over time. Feedback loops ensure that the rich get richer and the poor get poorer—also known as the Matthew Effect. These imbalances create opportunities for people who are aware of them and who understand how to exploit the unbalanced distribution. Another interesting aspect of the 80/20 principle is its recursive nature. Recursion in mathematics and computing refers to applying a function or principle repeatedly to itself: the 80/20 of the 80/20 of the 80/20. For instance, applying 80/20 to 80/20 results in 64/4, and applying the principle again results in 50/1. Current estimates show that 85.6% of the global wealth is owned by 8.6% of the total population; applying recursion with these same figures reveals that 73.3% of the global wealth is actually owned by 0.74% of the global population. Recursion can be used ad infinitum, but the difference becomes smaller with each iteration, i.e., recursion suffers from diminishing returns. The trick is using the 80/20 principle and figuring out the recursive 50/1. 

The same principle applies to language learning: one hour of learning doesn’t create one “unit” of improvement—however that is defined. The 80/20 principle is easily applied to learning vocabulary. First, a distinction should be made between active and passive vocabulary. Active vocabulary is made up of words that are frequently used and seen day-to-day, whereas passive vocabulary is the set of words that people understand but don’t frequently use. The average English native speakers possess a core vocabulary—active and passive—anywhere between 20,000 to 40,000 words. However, their active vocabulary is only around 5,000 words. And among those 5,000 words, roughly 2,000 words account for 80% of the language. Students who acquire vocabulary by prioritizing word frequency and word relevance will get the best bang for their buck, the highest return on their learning investment. Oxford Learner’s Dictionary has compiled a list of 3000 and 5000 most important words in the English language. These word lists are organized by the Common European Framework of Reference for Languages (CEFR) level, allowing students to practice vocabulary that matches their fluency and roughly determine their own language level.  In the beginning of language learning, having a specific list of words gives students motivation and direction. 

Vocabulary is the cornerstone of a language—the essential building block that forms a language. Prioritizing vocabulary helps students understand grammar points later on. When new grammar is introduced, students can focus on learning the grammar point instead of struggling with the meaning of a sentence. Even without understanding much of the grammar, an extensive vocabulary enables students to understand conversations and reading material—two critical inputs for successful language acquisition. At higher levels, students can guess the meaning of words based on context. Additionally, each student needs their own system for learning, remembering, and using vocabulary. Words should be acquired in context and frequently revisited to improve recall. Long-term retention is facilitated by spaced repetition of vocabulary. Some students use flashcards, others use spaced repetition systems (SRS) smartphone apps such as Anki, Quizlet, and TinyCards. Students should also find opportunities to use the new words multiple times in conversations or writing tasks. The strength of the word is increased with each repetition until it is logged into long-term memory. Nonetheless, vocabulary learning suffers from the use-it-or-lose-it phenonemon.  

At later stages of language learning, a one-word vocabulary list becomes less and less useful. In English, students have to start acquiring compound words, phrasal verbs, idioms, collocations, slang, and common expressions or phrases. They will need longer and more complicated constructions to communicate more complex thoughts. Memorizing individual words will be much less effective than seeing words or phrases in authentic contexts. Rote memorization can only take students so far. A mistake many students make is to write a word with its definition in their vocabulary notebook and then move on the next word. The definition of a word is not necessarily important. When encountering new vocabulary—whether as a single word or as a more complex phrase—students should ask: 

      • What part of speech does it belong to?
      • Is the meaning positive, negative, or neutral?
      • What does it mean exactly? 
      • How can I visualize this word (use Google Images)?
      • How do I pronounce it?
      • Can I use mnemonics to remember the sound? 
      • In which situations is it commonly used?
      • Is it related to anything I already know—similar sounds, synonyms, antonyms, words in a different language?
      • How would I use it in a sentence?
      • How do other people use it?
      • Are there any nuances that I should be aware of? 

Plus, students should memorize common daily phrases: What do native speakers say when meeting a new person? How would they order coffee? react to suprising news? answer the phone? end a professional e-mail? Knowing what to say at the right time signals social awareness and social competence, both of which are usually acquired with time and experience. When students learn these stock phrases early on in the language acquisition process, native speakers intuitively sense that the student is more familiar with the new language and that he or she has been immersed in the culture for a more extended period of time. The non-native speaker creates an impressive “illusion of fluency.” Transforming input to intake, meaning to actually feel competent when using new vocabulary, expressions, or grammar, might take several more weeks, months, and sometimes, years.  Learning anything new requires patience and time. It takes time for the brain to develop more robust and denser neural pathways and connect it to underlying neural networks. When was the last time you learned to do something after one practice session? And if you did, maybe you’re suffering from the Dunning-Kruger Effect: a tendency for unskilled people to overestimate their own skill level because they lack the ability to recognize their own incompetence. So find the right process, be patient, and have fun.

Further Reading

  • Learning Vocabulary in Another Language, I.S.P Nation (Victoria University of Wellington)