spyvssueTell them apart

Quick tell: spy is a noun, sue is a verb, so they fill different roles in a sentence.

Which to use

“spy” is a noun and “sue” is a verb - they look or sound alike but fill different roles in a sentence.

#4,799
“spy” frequency rank
#4,985
“sue” frequency rank
9784
confusion score

Side-by-Side Comparison

Feature spy sue
Definition A person who secretly watches and examines the actions of other individuals or organizations and gathers information on them (usually to gain an advantage). To file a legal action against someone, generally a non-criminal (civil) action.

Where the eye mixes spy and sue

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.

3 ch
spy
3 ch
sue

Why the eye confuses spy with sue

These two trip readers on the page rather than in the ear: spy is /spaɪ/ while sue is /sjuː/. Spoken aloud the problem disappears. In writing it persists, because they share most of their letters but differ in 2 positions, and the parts of speech differ too (noun vs verb), which is usually the fastest check. Our composite confusion score for this pair is 9784, derived from the frequency rank of both members and their visual similarity.

spy is recorded at frequency rank #4,799, classified as anoun, pronounced /spaɪ/. sue is at rank #4,985, tagged as averb, pronounced /sjuː/.

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 9784, this pair ranks #495,618 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of spy vs sue

Shared letters: s. Private to "spy": py. Private to "sue": eu.

"spy" · 3 letters · shape CCV  ·  "sue" · 3 letters · shape CVV

Frequently Asked Questions

Can "spy" and "sue" be used interchangeably?
No - they are not even the same part of speech. "spy" is a noun and "sue" a verb, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "spy" vs "sue" - which ranks higher?
"spy" is the more common of the two: it sits at frequency rank #4,799 in our English list, against #4,985 for "sue". 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 "spy" and "sue" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "spy" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "sue" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #495,618 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "spy" and "sue" also get mixed up with nearby pairs, the highest-scored neighbour is "sue vs sura". Nearby pair

Confusion rank #495,618 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