StasivsSTIWhich spelling fits?

Quick tell: Stasi is a name, STI is a noun, so they fill different roles in a sentence.

Which to use

“Stasi” is a name and “STI” is a noun - they look or sound alike but fill different roles in a sentence.

#37,706
“Stasi” frequency rank
#26,266
“STI” frequency rank
63972
confusion score

Side-by-Side Comparison

Feature Stasi STI
Definition The Ministry for State Security, secret police and intelligence organization of the German Democratic Republic (East Germany). Initialism of sexually transmitted infection (also S.T.I.).

Letter map: Stasi vs STI

Shared letters muted; letters that set Stasi and STI apart highlighted. Shared run: 3.

5 ch
Stasi
3 ch
STI

Part-of-speech tell for Stasi / STI

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: Stasi is aname and STIanoun. On the page they differ by 2 letter(s) in length. Our composite confusion score for this pair is 63972, derived from the frequency rank of both members and their visual similarity.

Stasi is recorded at frequency rank #37,706, classified as aname, pronounced /ˈstɑːzi/. STI is at rank #26,266, tagged as anoun.

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 63972, this pair ranks #80,139 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of Stasi vs STI

Shared letters: ist. Private to "Stasi": a. Private to "STI": -.

"Stasi" · 5 letters · shape CCVCV  ·  "STI" · 3 letters · shape CCV

Known mistypes of this pair

  • Stasisatsi · sstasi · stais · stsai · sttasi · tsasi

Frequently Asked Questions

Can "Stasi" and "STI" be used interchangeably?
No - they are not even the same part of speech. "Stasi" is a name and "STI" a noun, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "Stasi" vs "STI" - which ranks higher?
"STI" is the more common of the two: it sits at frequency rank #26,266 in our English list, against #37,706 for "Stasi". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

You've compared "Stasi" and "STI". Here's where to go from here.

  • Full dictionary entry for "Stasi" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "STI" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #80,139 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "Stasi" and "STI" also get mixed up with nearby pairs, the highest-scored neighbour is "staph vs Stasi". 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 #80,139 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