A student wants to improve vocabulary, so they collect rare words.
There is nothing wrong with rare words.
The problem appears when the same student still struggles with:
take responsibility for
raise a concern
result in / result from
The rare words look advanced.
The common words do more work.
Advanced vocabulary is not the same as rare vocabulary.
Frequency creates repeated returns
Oxford’s core vocabulary lists use frequency and learner relevance because some words appear again and again across reading, school, conversation and work.
Learning a high-value word deeply can pay back hundreds of times.
Common words can be deceptively complex
Take issue:
a difficult issue
the latest issue of a magazine
issue a statement
issue a warning
Or point:
point of view
main point
data point
point to the answer
Frequency does not guarantee mastery.
Depth multiplies utility
Take evidence.
Useful patterns include:
provide evidence
strong evidence
limited evidence
evidence suggests
evidence for / against
One common word becomes a phrase network.
Rare-word learning can create false progress
A new obscure word is easy to count on a flashcard.
But can the student use it naturally?
Do they know its collocations, register and connotation?
Recognition is easier to measure than usable control.
Frequency is not the only priority
Students also need specialised and low-frequency words when the subject requires them.
A Biology term may be rare in everyday English but essential in Biology.
The better principle is:
priority should reflect utility.
Advanced can mean deeper
Consider the ordinary verb take.
take responsibility
take action
take part
take effect
take into account
take a risk
The spelling is simple. The phrase control is advanced.
Common academic words organise knowledge
factor
source
evidence
function
process
role
approach
result
relationship
These words travel across Science, History, Geography, Mathematics and English.
They are infrastructure for reasoning.
Productive vocabulary matters
Current research on adolescent writing continues to find relationships between productive vocabulary knowledge and lexical quality in writing.
The practical lesson is:
words must become retrievable, not merely recognisable.
Frequency and range are different
A word may be frequent in one narrow field.
Another may appear across many fields.
Cross-subject words such as significant can be particularly valuable because they travel.
Sense frequency matters
A common word may have many dictionary senses, but some are much more frequent than others.
Students do not need every rare sense immediately.
Learn the dominant, useful senses first, then expand.
Rare words earn their place through precision
Nostalgic may be useful because it names a particular emotional relationship to the past.
The word earns its complexity.
A rare synonym that merely makes a sentence less natural does not.
Common words carry sophisticated reasoning
may
although
unless
whereas
despite
therefore
These are ordinary words, yet they control certainty, concession, condition and logic.
Sophistication can live inside common language.
A prioritisation test
- Frequency: will I meet this often?
- Range: does it appear across contexts?
- Relevance: do I need it for school or reading?
- Depth: do I know its main senses and collocations?
- Retrieval: can I use it without looking?
A three-tier vocabulary notebook
Tier A: high-frequency deep-control words.
Tier B: academic and cross-subject words.
Tier C: lower-frequency precision words.
Now every word has a reason for being learned.
Hilary Mantel as a high-level lens
Powerful prose does not depend on making every word rare. Common verbs, concrete nouns and exact observations can carry enormous force.
The transferable principle is selection, not imitation.
AI can make rarity look like sophistication
Ask an AI to “make this more sophisticated” and it may replace familiar words with lower-frequency synonyms.
Audit:
Did meaning become more exact?
Did register change?
Is the collocation natural?
Does the new word earn its complexity?
Connections eduKateAI can learn
frequency → repeated exposure → utility
common word → multiple senses + collocations → hidden depth
productive knowledge → retrieval → writing use
rare word → possible precision, not automatic sophistication
The public principle is that vocabulary value should be judged by usable semantic reach, not unusual appearance.
Related eduKateSG resources
Research basis
This article draws on Oxford 3000/5000 principles and current research on ultra-frequent words, vocabulary use in writing and lexical sophistication.