slyvssonTell them apart

Quick tell: sly is a adjective, son is a noun, so they fill different roles in a sentence.

Which to use

“sly” is an adjective and “son” is a noun - they look or sound alike but fill different roles in a sentence.

#17,246
“sly” frequency rank
#534
“son” frequency rank
17780
confusion score

Side-by-Side Comparison

Feature sly son
Definition Artfully cunning; secretly mischievous; wily. One's male offspring.

Where the eye mixes sly and son

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

3 ch
sly
3 ch
son

Look-alike desk: sly vs son

These two trip readers on the page rather than in the ear: sly is /slaɪ/ while son is /sʌn/. 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 (adjective vs noun), which is usually the fastest check. Our composite confusion score for this pair is 17780, derived from the frequency rank of both members and their visual similarity.

sly is recorded at frequency rank #17,246, classified as anadj, pronounced /slaɪ/. son is at rank #534, tagged as anoun, pronounced /sʌn/.

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 17780, this pair ranks #449,179 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of sly vs son

Shared letters: s. Private to "sly": ly. Private to "son": no.

"sly" · 3 letters · shape CCV  ·  "son" · 3 letters · shape CVC

Frequently Asked Questions

Is swapping "sly" for "son" ever safe?
No - they are not even the same part of speech. "sly" is an adjective and "son" a noun, so a sentence built for one is usually ungrammatical with the other.
In ordinary English text, does "sly" or "son" show up more?
"son" is the more common of the two: it sits at frequency rank #534 in our English list, against #17,246 for "sly". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Useful next steps

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

  • Full dictionary entry for "sly" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "son" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #449,179 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "sly" and "son" also get mixed up with nearby pairs, the highest-scored neighbour is "Sif vs sly". Nearby pair

Confusion rank #449,179 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