alienvsalterWhat's the difference?

Quick tell: alien is a noun, alter is a verb, so they fill different roles in a sentence.

Which to use

“alien” is a noun and “alter” is a verb - they look or sound alike but fill different roles in a sentence.

#4,347
“alien” frequency rank
#6,540
“alter” frequency rank
10887
confusion score

Side-by-Side Comparison

Feature alien alter
Definition A person, animal, plant, or other thing which is from outside the family, group, organization, or territory under consideration. To change the form or structure of.

Where the spellings diverge

Shared letters are muted; the letters that actually set alien and alter apart are highlighted. They share 3 letters in sequence, which is exactly why the eye skips the difference.

5 ch
alien
5 ch
alter

Spelling & Dictionary Insight

alien and alter form a confusable pair in the English index, two distinct headwords that are easily confused because they look alike, sound alike, or both. They share most of their letters but differ in 2 positions - close enough that the eye skips over the difference, far enough that meaning fully diverges. Our composite confusion score for this pair is 10887, derived from the frequency rank of both members and their visual similarity.

alien is recorded at frequency rank #4,347, classified as anoun, pronounced /ˈeɪ.li.ən/. alter is at rank #6,540, tagged as averb, pronounced /ˈɒl.tə/.

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 10887, this pair ranks #489,995 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Frequency comparison

alien#4,347
alter#6,540

Source: FrequencyWords open word-frequency list

Frequently Asked Questions

Can "alien" and "alter" be used interchangeably?
No, "alien" and "alter" have distinct meanings and cannot be swapped without changing the meaning of a sentence. Understanding the specific definition and context for each word is essential for correct usage.

Remembering alien vs alter

The fastest way to pick the right one every time.

  • Check the role first: if you need a noun, it's “alien”; for a verb, it's “alter”.
  • See each word in full, definition, IPA, etymology and its other confusables. Full “alien” entry
  • Browse more pairs most likely to be confused. Most confusable

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list FrequencyWords open word-frequency list