How to build your vocabulary
as an adult

How adults gain words

An average 20-year-old native speaker of American English knows about 42,000 lemmas, and between 20 and 60 people learn about 6,000 more, roughly one every two days (Brysbaert and colleagues, Frontiers in Psychology 7, 2016). Almost all of them come from reading and listening, not from study.

That route is slow for any single word. A meta-analysis of 20 experiments found that readers learn about 15% of the unknown words they meet in normal reading (Swanborn and de Glopper, Review of Educational Research 69(3), 1999). Most unfamiliar words need several meetings before they stay. Building a vocabulary on purpose means giving the words you care about those meetings, instead of waiting for chance.

Read a little above your level

• Choose writing with more words than you use. Long-form journalism, essays, good novels, and the serious end of your own field. Social media and news headlines repeat the words you already know.
• Aim for a page with a few new words, not dozens. If every paragraph has one word you would look up, the level is right; if every line does, the text is too hard to learn from.
• Read regularly. Twenty minutes a day meets far more words than a weekend binge, and brings back the ones you met last week.
• Listen too. Podcasts, lectures and talks bring the spoken words that print rarely uses.

Keep the words you meet

This is the step most advice skips. A word you looked up and moved on from is usually gone within a week. Write it down, with three things:

1. The word in its dictionary form: obfuscate, not obfuscated.
2. A plain definition in the same language, in simpler words than the word itself. A learner’s dictionary writes definitions this way; a thesaurus synonym alone is too vague.
3. The sentence you met it in. It shows how the word is used, what it goes with, and its tone.

Keep a few, not every unfamiliar word: the ones you would like to use, or that you met twice. Five a week, kept and reviewed, beats fifty skimmed. More on the notebook itself: Vocabulary notebook: how to make one.

Learn the parts

Many longer English words are built from Latin and Greek parts. Knowing a few helps you guess a new word and remember it:

• bene- (well): benefit, benevolent, benign.
• -cracy (rule by): democracy, bureaucracy, meritocracy.
• mis- (wrongly): misread, misjudge, misnomer.

Treat parts as clues, not proof: inflammable means the same as flammable. Check the dictionary, and keep the definition you find.

Use them, then review them

• Use a new word within the week. In an e-mail, a message, a conversation. Using a word moves it from words you recognise to words you reach for.
• Test yourself from the definition. See “to make something unclear on purpose” and find obfuscate. Recalling a word does more for memory than rereading it; active recall for vocabulary explains the research.
• Review at growing gaps. Tomorrow, in a few days, in a week, in three weeks. The forgetting curve shows why the gaps can grow.

Word-of-the-day apps or your own words

Word-of-the-day apps and newsletters are pleasant and easy: one interesting word a day, chosen for you, often with its history. They show you words; they rarely bring them back. Your own words, from your own reading, come with a sentence you remember and a reason to know them. Many people use both: a word of the day for curiosity, and a notebook for the words they want to keep.

How Lexpad helps

Made by the author of this page

An English notebook with English definitions

• Choose English on both sides when you create a notebook. Lexpad’s AI then writes each card the way a learner’s dictionary does: short definitions in plain English, a plain synonym where one exists, and each example with a plain-words paraphrase instead of a translation.
• It works for any of 81 languages: a French notebook with French definitions, for example.
• Save a word from any web page with the browser extension, from a Kindle, or by typing it; keep the sentence as the example.
• Five boxes bring each word back after 1, 3, 7 and 21 days while you know it, and much later once it is mastered. Cards ask from the definition as well as from the word.

Open in LexpadAll downloads

Free account, no card. Apps: Mac · Windows · Android · iPhone

Sources, read 25 October 2026

• Brysbaert, M., Stevens, M., Mandera, P. and Keuleers, E. (2016). How many words do we know? Frontiers in Psychology 7, 1116.
• Swanborn, M. S. L. and de Glopper, K. (1999). Incidental word learning while reading: a meta-analysis. Review of Educational Research 69(3), 261–285.