ergvsergoTell them apart

Quick tell: erg is a noun, ergo is an adverb, so they fill different roles in a sentence.

Which to use

“erg” is a noun and “ergo” is an adverb - they look or sound alike but fill different roles in a sentence.

#48,222
“erg” frequency rank
#30,025
“ergo” frequency rank
78247
confusion score

Side-by-Side Comparison

Feature erg ergo
Definition A unit of work or energy, being the amount of work done by a force of one dyne applied through a distance of one centimeter. Equal to 10⁻⁷ joules. Consequently, therefore, or thus.

Where the eye mixes erg and ergo

Muted = shared; highlighted = the visual trap. They share 3 letters in sequence. erg runs 3 letters (VCC) against ergo's 4 (VCCV) - the length gap alone is often enough to separate them once you know to check it.

3 ch
erg
4 ch
ergo

Visual trap between erg and ergo

These two trip readers on the page rather than in the ear: erg is /ɜːɡ/ while ergo is /ˈɛɚɡoʊ/. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 extra letter(s) - “erg” sits inside “ergo”, and the parts of speech differ too (noun vs adverb), which is usually the fastest check. Our composite confusion score for this pair is 78247, derived from the frequency rank of both members and their visual similarity.

erg is recorded at frequency rank #48,222, classified as anoun, pronounced /ɜːɡ/. ergo is at rank #30,025, tagged as anadv, pronounced /ˈɛɚɡoʊ/.

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 78247, this pair ranks #25,087 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of erg vs ergo

Shared letters: egr. Private to "erg": -. Private to "ergo": o.

"erg" · 3 letters · shape VCC  ·  "ergo" · 4 letters · shape VCCV

Known mistypes of this pair

  • ergo ← egro · erggo · erog · errgo · rego

Frequently Asked Questions

Is swapping "erg" for "ergo" ever safe?
No - they are not even the same part of speech. "erg" is a noun and "ergo" an adverb, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "erg" or "ergo"?
"ergo" is the more common of the two: it sits at frequency rank #30,025 in our English list, against #48,222 for "erg". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Eye-level mix-up between "erg" and "ergo" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "erg" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "ergo" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #25,087 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "erg" and "ergo" also get mixed up with nearby pairs, the highest-scored neighbour is "erg vs Eri". Nearby pair
  • Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes

Confusion rank #25,087 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list