AIS vs at, What's the Difference?

Which to use

“AIS” is a noun and “at” is a preposition - they look or sound alike but fill different roles in a sentence.

#26,670
“AIS” frequency rank: #21
“at” frequency rank: 26691
confusion score

Side-by-Side Comparison

Feature	AIS	at
Definition	Initialism of automatic identification system, as an element of the Global Marine Distress and Safety System GMDSS.	In, near, or in the general vicinity of (a particular place).

Where the eye mixes AIS and at

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.

3 ch

AIS

2 ch

Why the eye confuses AIS with at

These two trip readers on the page rather than in the ear: AIS is /ˈeɪ ˈaɪ ˈɛs/ while at is /æt/. 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 (noun vs preposition), which is usually the fastest check. Our composite confusion score for this pair is 26691, derived from the frequency rank of both members and their visual similarity.

AIS is recorded at frequency rank #26,670, classified as anoun, pronounced /ˈeɪ ˈaɪ ˈɛs/. at is at rank #21, tagged as aprep, pronounced /æt/.

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 26691, this pair ranks #384,792 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of AIS vs at

Shared letters: a. Private to "AIS": is. Private to "at": t.

"AIS" · 3 letters · shape VVC · "at" · 2 letters · shape VC

Frequently Asked Questions

Do "AIS" and "at" mean the same thing in a sentence?

No - they are not even the same part of speech. "AIS" is a noun and "at" a preposition, so a sentence built for one is usually ungrammatical with the other.

Frequency check: "AIS" vs "at" - which ranks higher?

"at" is the more common of the two: it sits at frequency rank #21 in our English list, against #26,670 for "AIS". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

After this comparison

Eye-level mix-up between "AIS" and "at" is sorted above. Next: full entries or other pairs that share a letter shape.

Full dictionary entry for "AIS" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "at" - compare definitions side by side with the headword page. Word entry
This pair ranks #384,792 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
"AIS" and "at" also get mixed up with nearby pairs, the highest-scored neighbour is "AIS vs amb". Nearby pair

Confusion rank #384,792 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.