Which to use
“SIDS” is a noun and “so's” is a contraction - they look or sound alike but fill different roles in a sentence.
- #49,048
- “SIDS” frequency rank
- #38,171
- “so's” frequency rank
- 87219
- confusion score
Side-by-Side Comparison
| Feature | SIDS | so's |
|---|---|---|
| Definition | Acronym of sudden infant death syndrome. | So that, in order that. |
Letter map: SIDS vs so's
Shared letters muted; letters that set SIDS and so's apart highlighted. Shared run: 2. SIDS runs 4 letters (CVCC) against so's's 3 (CVC) - the length gap alone is often enough to separate them once you know to check it.
Role in the sentence - SIDS and so's
Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: SIDS is anoun and so'sacontraction. On the page they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 87219, derived from the frequency rank of both members and their visual similarity.
SIDS is recorded at frequency rank #49,048, classified as anoun. so's is at rank #38,171, tagged as acontraction.
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 87219, this pair ranks #7,916 of 530,003 scored English confusable pairs - among the most confusable pairs.
Orthographic DNA of SIDS vs so's
Shared letters: s. Private to "SIDS": di. Private to "so's": o.
"SIDS" · 4 letters · shape CVCC · "so's" · 3 letters · shape CVC
Known mistypes of this pair
- SIDS ← isds · sdis · sidds · sidss · sisd · ssids
Frequently Asked Questions
Do "SIDS" and "so's" mean the same thing in a sentence?
Which is more common, "SIDS" or "so's"?
What to do next
Done with this confusable. These links stay specific to "SIDS" and "so's".
- Full dictionary entry for "SIDS" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "so's" - compare definitions side by side with the headword page. Word entry
- This pair ranks #7,916 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "SIDS" and "so's" also get mixed up with nearby pairs, the highest-scored neighbour is "SIDS vs suds". 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 #7,916 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.