agovsatomWhat's the difference?

Quick tell: ago is a postp, atom is a noun, so they fill different roles in a sentence.

Which to use

“ago” is a postp and “atom” is a noun - they look or sound alike but fill different roles in a sentence.

#365
“ago” frequency rank
#10,813
“atom” frequency rank
11178
confusion score

Side-by-Side Comparison

Feature ago atom
Definition Before now, before the present time The smallest possible amount of matter which still retains its identity as a chemical element, now known to consist of a nucleus surrounded by electrons.

Where the eye mixes ago and atom

Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.

3 ch
ago
4 ch
atom

Visual trap between ago and atom

These two trip readers on the page rather than in the ear: ago is /əˈɡəʊ/ while atom is /ˈætəm/. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 letter(s) in length, and the parts of speech differ too (postp vs noun), which is usually the fastest check. Our composite confusion score for this pair is 11178, derived from the frequency rank of both members and their visual similarity.

ago is recorded at frequency rank #365, classified as apostp, pronounced /əˈɡəʊ/. atom is at rank #10,813, tagged as anoun, pronounced /ˈætəm/.

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 11178, this pair ranks #488,472 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of ago vs atom

Shared letters: ao. Private to "ago": g. Private to "atom": mt.

"ago" · 3 letters · shape VCV  ·  "atom" · 4 letters · shape VCVC

Known mistypes of this pair

  • atomaotm · atmo · atomm · attom · taom

Frequently Asked Questions

Can "ago" and "atom" be used interchangeably?
No - they are not even the same part of speech. "ago" is a postp and "atom" a noun, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "ago" or "atom"?
"ago" is the more common of the two: it sits at frequency rank #365 in our English list, against #10,813 for "atom". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

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

  • Full dictionary entry for "ago" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "atom" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #488,472 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "ago" and "atom" also get mixed up with nearby pairs, the highest-scored neighbour is "APM vs atom". 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 #488,472 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