Can 'infallible' be used to describe people?

Yes, but it often carries a tone of criticism or hyperbole, as it suggests impossible perfection (e.g., 'He acts as if he's infallible'). It is used seriously in specific contexts like 'the Pope is considered infallible when speaking ex cathedra on matters of faith.'

What is the difference between 'infallible' and 'infallible'?

There is no difference; the second is a spelling error. The correct spelling is 'infallible' (double 'l').

Is 'infallible' a common word?

No, it is a low-frequency, C1-level word. More common synonyms in everyday speech are 'reliable', 'foolproof', or 'unfailing'.

Does 'infallible' have a noun form?

Yes, the noun is 'infallibility' (e.g., the infallibility of the system). The adverb 'infallibly' exists but is very rarely used.

infallible

UK/ɪnˈfæl.ə.bəl/US/ɪnˈfæl.ə.bəl/

Formal, literary

My Flashcards

Definition

Meaning

Incapable of making mistakes or being wrong; never failing.

Something (a method, system, person, or object) that is completely dependable or certain to work as intended.

Linguistics

Semantic Notes

Often implies an absolute, almost god-like quality of perfection. Can carry a negative connotation of arrogance or unreasonableness when applied to people. More commonly used to describe methods, systems, or principles.

Dialectal Variation

British vs American Usage

Differences

No significant lexical or grammatical differences. The term carries the same meaning and usage patterns in both varieties.

Connotations

Slightly more likely to be used in religious or philosophical contexts in British English (e.g., papal infallibility). In American English, it may appear more in business or self-help contexts (e.g., infallible strategy).

Frequency

Low-frequency in both varieties, with comparable usage levels.

Vocabulary

Collocations

strong

papal infallibilityinfallible methodinfallible logicinfallible guideinfallible proof

medium

infallible systeminfallible memoryinfallible judgmentinfallible testconsidered infallible

weak

infallible planinfallible remedyinfallible instinctinfallible signinfallible accuracy

Grammar

Valency Patterns

be + infallibleconsider + something/someone + infallibleregard + as + infallibleprove + infallible

Vocabulary

Synonyms

Strong

flawlessimpeccableunerringperfectirrefutable

Neutral

unfailingfoolproofcertainreliabledependable

Weak

trustworthysoundsureaccurateconsistent

Vocabulary

Antonyms

fallibleunreliableimperfectfaultyerroneous

Phrases

Idioms & Phrases

“Nobody is infallible.”
“There is no infallible recipe for success.”

Usage

Context Usage

Business

Used to describe a supposedly guaranteed strategy or investment method (often sceptically).

Academic

Used in philosophy, theology, and logic to discuss the limits of knowledge and certainty.

Everyday

Used humorously or hyperbolically (e.g., 'My grandmother's recipe is infallible.').

Technical

Used in computing/engineering for fault-tolerant systems, though 'fault-tolerant' is more common.

Examples

By Part of Speech

adverb

British English

infallibly (rare)
The method worked infallibly for decades.
He could infallibly predict the market's turns.

American English

infallibly (rare)
The device functioned infallibly in all trials.
She was infallibly polite, even under pressure.

adjective

British English

His judgement was considered infallible on matters of antique valuation.
They sought an infallible test for the virus.

American English

No system is truly infallible under extreme stress.
She had an infallible knack for remembering birthdays.

Examples

By CEFR Level

My sat-nav is not infallible; it sometimes makes mistakes.
He believes his lucky charm is infallible.

The scientist warned that no theoretical model is completely infallible.
Her infallible memory for details made her an excellent researcher.

The doctrine of papal infallibility is a cornerstone of Catholic theology.
They operated under the infallible logic of the algorithm, blind to its potential ethical flaws.

Learning

Memory Aids

Mnemonic

IN (not) + FALLIBLE (able to make errors) = Not able to make errors. Think of the Pope's 'infallible' pronouncements from the Vatican, which are considered incapable of error.

Conceptual Metaphor

CERTAINTY IS PERFECTION / ERROR-PRONE IS WEAK

Watch out

Common Pitfalls

Translation Traps (for Russian speakers)

Do not confuse with 'безошибочный' (error-free) for objects/actions and 'непогрешимый' (morally/authoritatively faultless) for people/ideals. 'Infallible' covers both concepts.

Common Mistakes

Using it to mean 'very good' rather than 'incapable of error' (e.g., 'He's an infallible guitarist' is hyperbolic and incorrect).
Confusing spelling with 'infallable' (correct is infallible).

Practice

Quiz

Fill in the gap

While the plan seemed in theory, its practical application revealed several critical flaws.

Multiple Choice

In which context is the use of 'infallible' MOST appropriate?

FAQ

Frequently Asked Questions

: Yes, but it often carries a tone of criticism or hyperbole, as it suggests impossible perfection (e.g., 'He acts as if he's infallible'). It is used seriously in specific contexts like 'the Pope is considered infallible when speaking ex cathedra on matters of faith.'
: There is no difference; the second is a spelling error. The correct spelling is 'infallible' (double 'l').
: No, it is a low-frequency, C1-level word. More common synonyms in everyday speech are 'reliable', 'foolproof', or 'unfailing'.
: Yes, the noun is 'infallibility' (e.g., the infallibility of the system). The adverb 'infallibly' exists but is very rarely used.