This C1 list adds the first 50 words at the level above B1, and it changes the kind of word you learn. Up to B1 the lists were mostly concrete: food, travel, work, feelings. C1 is where the abstract and the formal arrive, the words you meet in a report, a review or a debate and need in order to argue a point rather than describe a scene. The fifty below are grouped into five sets of ten, with the part of speech and one plain example sentence each. Better still, work through the B1 list first if you have not already, because the C1 words sit on top of it.
Why these 50 words come next
At C1 the exam and the workplace both ask you to do three things with language: take a position, support it with evidence, and describe something precisely without overstating it. The sets below follow that order, so the list doubles as a speaking plan. Several words appear in fixed partnerships rather than alone, and our guide to collocations explains why those pairings are worth learning as units.
Set 1: argument and opinion (10 words)
assert (verb) — The report asserts that costs will fall next year.
concede (verb) — She conceded that the first plan was weaker.
contend (verb) — Critics contend that the rule is too broad.
justify (verb) — Nothing can justify a delay of six months.
undermine (verb) — The leak undermined public trust in the inquiry.
plausible (adjective) — That is a plausible explanation, but not the only one.
coherent (adjective) — The essay needs a more coherent structure.
nuance (noun) — The nuance is easy to miss in translation.
premise (noun) — The whole argument rests on a false premise.
rebuttal (noun) — His rebuttal was shorter than the speech it answered.
Set 2: change and consequence (10 words)
inevitable (adjective) — Some disagreement is inevitable in a large team.
profound (adjective) — The change had a profound effect on the industry.
gradual (adjective) — Recovery was gradual but steady.
trigger (verb) — The announcement triggered a wave of resignations.
exacerbate (verb) — Delays only exacerbated the shortage.
mitigate (verb) — Insurance can mitigate the loss, not remove it.
entail (verb) — The role entails frequent travel and early starts.
subsequent (adjective) — Subsequent studies reached the same conclusion.
aftermath (noun) — In the aftermath, the rules were rewritten.
contingent (adjective) — Further funding is contingent on results.
Set 3: evidence and accuracy (10 words)
credible (adjective) — The witness gave a credible account of the morning.
ambiguous (adjective) — The wording of the clause is ambiguous.
discrepancy (noun) — There is a discrepancy between the two reports.
verify (verb) — We could not verify the figure independently.
corroborate (verb) — A second source corroborated the story.
infer (verb) — From the data we can infer a slow trend upwards.
arbitrary (adjective) — The cut-off date seems entirely arbitrary.
meticulous (adjective) — She kept meticulous records of every payment.
scrutiny (noun) — The claim did not survive close scrutiny.
indicative (adjective) — The rise is indicative of stronger demand.
Set 4: work and institutions (10 words)
initiative (noun) — She took the initiative on the project.
incentive (noun) — Tax relief is an incentive to invest early.
mandate (noun) — The committee has a clear mandate to review costs.
consensus (noun) — There was no consensus among the members.
stakeholder (noun) — Every stakeholder was consulted before the vote.
streamline (verb) — The team streamlined the approval process.
accountable (adjective) — Managers are accountable for the budget.
feasible (adjective) — The plan is technically feasible within a year.
redundant (adjective) — Two of the roles became redundant in the merger.
preliminary (adjective) — These are preliminary findings, not conclusions.
Set 5: description and emphasis (10 words)
striking (adjective) — The resemblance between the two photographs is striking.
subtle (adjective) — There is a subtle difference between the two verbs.
vivid (adjective) — She gave a vivid description of the market at dawn.
mundane (adjective) — The work is mundane but necessary.
elaborate (adjective) — The ceremony was more elaborate than expected.
scarcely (adverb) — He scarcely spoke during the meeting.
invariably (adverb) — Prices invariably rise before the holiday.
albeit (conjunction) — The plan worked, albeit slowly.
nonetheless (adverb) — The results are modest, nonetheless encouraging.
hence (adverb) — The road was closed, hence the long detour.
How to learn these 50 words at the C1 stage
Ten words a day, one set at a time, is a realistic pace. Read the word, cover the example, and say a sentence of your own before you check whether the meaning holds. Then put the word into a partnership, because C1 words rarely travel alone: justify a decision, mitigate a risk, a coherent argument, subsequent events. A word you have only read stays passive; a word you have used in a sentence about your own life is the one that turns up when you need it.
Keep a running page of new words as you meet them in reading and note the sentence you found them in. The list above is a starting order, not a boundary, and the habit of collecting matters more than the fifty themselves.
How to test yourself on these 50 words
Use two passes. In the first, cover the English and produce the word from the meaning or from the example sentence with one gap. In the second, do the reverse and produce the meaning from the word alone. Only the second pass shows whether the word is available for speaking, because recognising a word is far easier than producing it. Words that fail twice go onto a short review card with their example sentence; our guide to the keyword mnemonic method covers what to write on it, and spaced repetition explains when to look at it again.
Frequently asked questions
What does C1 level mean in language learning?
C1 is the fifth level on the six-step scale used by the Common European Framework, one step above B1 and B2 and one below C2. At C1 a learner can follow a long argument, express ideas precisely, and write clear, well-structured text on complex subjects, which is why the vocabulary shifts towards abstract and formal words.
How many words do I need at C1?
Published estimates put receptive knowledge at roughly eight thousand word families at C1, but the useful number is much smaller. A working set of one thousand to two thousand well-chosen abstract and formal words, used often, carries most everyday academic and professional reading.
Are these 50 words different from the B1 lists?
Yes. The earlier lists stayed concrete: feelings, times of day, work routines, travel and food. This list is almost entirely abstract or formal, so it adds new meaning rather than repeating the same words with longer definitions.
How should I learn C1 words so they stick?
Learn them in partnerships and in your own sentences rather than as single items. Ten words a day, each used once in speech or writing and reviewed at growing intervals, will hold better than a hundred words read twice without use.
How can I test myself on these 50 words?
Test production, not recognition. Cover the English, read the example sentence with one gap, and say the missing word before you check. Do the same pass again three days later and keep only the failures on your review card.
Author & review
Author: our editorial team, which prepares the practice content and worksheet data.
Review: character forms, stroke order and pronunciation data are checked against standard references; every example is human-reviewed before publishing.
Nature of the content: these are practice aids for parents and teachers — not a substitute for classroom teaching or professional advice.
Last reviewed: 2026-09-13 · re-reviewed quarterly and within 7 days of significant changes.
Corrections: if you spot an error, tell us via the contact page — we verify and correct within 2 working days.