underagevsundertakeWhich spelling fits?

Quick tell: underage is a adjective, undertake is a verb, so they fill different roles in a sentence.

Which to use

“underage” is an adjective and “undertake” is a verb - they look or sound alike but fill different roles in a sentence.

#15,727
“underage” frequency rank
#10,787
“undertake” frequency rank
26514
confusion score

Side-by-Side Comparison

Feature underage undertake
Definition Below the legal age (usually age 18) for some activity, such as consuming alcohol or engaging in sexual intercourse. To take upon oneself; to start, to embark on (a specific task etc.).

Where the eye mixes underage and undertake

Muted = shared; highlighted = the visual trap. They share 7 letters in sequence. underage runs 8 letters (VCCVCVCV) against undertake's 9 (VCCVCCVCV) - the length gap alone is often enough to separate them once you know to check it.

8 ch
underage
9 ch
undertake

Look-alike desk: underage vs undertake

These two trip readers on the page rather than in the ear: underage is /ˌʌndəɹˈeɪd͡ʒ/ while undertake is /ˌʌndəˈteɪk/. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 letter(s) in length, and the parts of speech differ too (adjective vs verb), which is usually the fastest check. Our composite confusion score for this pair is 26514, derived from the frequency rank of both members and their visual similarity.

underage is recorded at frequency rank #15,727, classified as anadj, pronounced /ˌʌndəɹˈeɪd͡ʒ/. undertake is at rank #10,787, tagged as averb, pronounced /ˌʌndəˈteɪk/.

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 26514, this pair ranks #386,136 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of underage vs undertake

Shared letters: adenru. Private to "underage": g. Private to "undertake": kt.

"underage" · 8 letters · shape VCCVCVCV  ·  "undertake" · 9 letters · shape VCCVCCVCV

Known mistypes of this pair

  • underage ← nuderage · udnerage · undderage · undearge · underaeg · underagge · undergae · underrage
  • undertake ← nudertake · udnertake · unddertake · underatke · underrtake · undertaek · undertakke · undertkae

Frequently Asked Questions

Do "underage" and "undertake" mean the same thing in a sentence?
No - they are not even the same part of speech. "underage" is an adjective and "undertake" a verb, so a sentence built for one is usually ungrammatical with the other.
In ordinary English text, does "underage" or "undertake" show up more?
"undertake" is the more common of the two: it sits at frequency rank #10,787 in our English list, against #15,727 for "underage". 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 "underage" and "undertake" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "underage" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "undertake" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #386,136 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "underage" and "undertake" also get mixed up with nearby pairs, the highest-scored neighbour is "underage vs underlie". 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 #386,136 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