flaskvsfrankWhich spelling fits?

Quick tell: flask is a noun, frank is an adjective, so they fill different roles in a sentence.

Which to use

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

#22,379
“flask” frequency rank
#1,828
“frank” frequency rank
24207
confusion score

Side-by-Side Comparison

Feature flask frank
Definition A narrow-necked vessel of metal or glass, used for various purposes; as of sheet metal, to carry gunpowder in; or of wrought iron, to contain quicksilver; or of glass, to heat water in, etc. Honest, especially in a manner that seems slightly blunt; candid; not reserved or disguised.

Where the eye mixes flask and frank

Muted = shared; highlighted = the visual trap. They share 3 letters in sequence.

5 ch
flask
5 ch
frank

Why the eye confuses flask with frank

These two trip readers on the page rather than in the ear: flask is /ˈflɑːsk/ while frank is /ˈfɹæŋk/. 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 adjective), which is usually the fastest check. Our composite confusion score for this pair is 24207, derived from the frequency rank of both members and their visual similarity.

flask is recorded at frequency rank #22,379, classified as anoun, pronounced /ˈflɑːsk/. frank is at rank #1,828, tagged as anadj, pronounced /ˈfɹæŋk/.

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 24207, this pair ranks #403,696 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of flask vs frank

Shared letters: afk. Private to "flask": ls. Private to "frank": nr.

"flask" · 5 letters · shape CCVCC  ·  "frank" · 5 letters · shape CCVCC

Known mistypes of this pair

  • flaskfalsk · fflask · flaks · flaskk · flassk · fllask · flsak · lfask
  • frankfarnk · ffrank · frakn · frankk · frannk · frnak · frrank · rfank

Frequently Asked Questions

Can "flask" and "frank" be used interchangeably?
No - they are not even the same part of speech. "flask" is a noun and "frank" an adjective, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "flask" vs "frank" - which ranks higher?
"frank" is the more common of the two: it sits at frequency rank #1,828 in our English list, against #22,379 for "flask". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.

  • Full dictionary entry for "flask" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "frank" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #403,696 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "flask" and "frank" also get mixed up with nearby pairs, the highest-scored neighbour is "flail vs flask". 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 #403,696 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