infervsinfirmWhat's the difference?

Quick tell: infer is a verb, infirm is an adjective, so they fill different roles in a sentence.

Which to use

“infer” is a verb and “infirm” is an adjective - they look or sound alike but fill different roles in a sentence.

#23,568
“infer” frequency rank
#46,546
“infirm” frequency rank
70114
confusion score

Side-by-Side Comparison

Feature infer infirm
Definition To introduce (something) as a reasoned conclusion; to conclude by reasoning or deduction, as from premises or evidence. Weak or ill, not in good health.

Where the spellings diverge

Shared letters are muted; the letters that actually set infer and infirm apart are highlighted. They share 4 letters in sequence, which is exactly why the eye skips the difference.

5 ch
infer
6 ch
infirm

Spelling & Dictionary Insight

infer and infirm form a confusable pair in the English index, two distinct headwords that are easily confused because they look alike, sound alike, or both. They differ by 1 letter(s) in length - close enough that the eye skips over the difference, far enough that meaning fully diverges. Our composite confusion score for this pair is 70114, derived from the frequency rank of both members and their visual similarity.

infer is recorded at frequency rank #23,568, classified as averb, pronounced /ɪnˈfɜː/. infirm is at rank #46,546, tagged as anadj, pronounced /ɪnˈfɜːm/.

Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.

With a confusion score of 70114, this pair ranks #51,875 of 530,003 scored English confusable pairs - among the most confusable pairs.

Frequency comparison

infer#23,568
infirm#46,546

Source: FrequencyWords open word-frequency list

Frequently Asked Questions

Can "infer" and "infirm" be used interchangeably?
No, "infer" and "infirm" have distinct meanings and cannot be swapped without changing the meaning of a sentence. Understanding the specific definition and context for each word is essential for correct usage.

Remembering infer vs infirm

The fastest way to pick the right one every time.

  • Check the role first: if you need a verb, it's “infer”; for an adjective, it's “infirm”.
  • See each word in full, definition, IPA, etymology and its other confusables. Full “infer” entry
  • Browse more pairs most likely to be confused. Most confusable

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list FrequencyWords open word-frequency list