Which to use
“A4” is a name and “AD” is an adverb - they look or sound alike but fill different roles in a sentence.
- #18,471
- “A4” frequency rank
- #1,779
- “AD” frequency rank
- 20250
- confusion score
Side-by-Side Comparison
| Feature | A4 | AD |
|---|---|---|
| Definition | A4 class, a class of steam locomotive used on the London and North Eastern Railway. | Initialism of Anno Domini (borrowed from Latin); in the year of our Lord. |
Letter map: A4 vs AD
Shared letters muted; letters that set A4 and AD apart highlighted. Shared run: 1.
Spelling & Dictionary Insight
Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: A4 is aname and ADanadverb. On the page they differ by a single letter - 4 in “A4” becomes d in “AD”. Our composite confusion score for this pair is 20250, derived from the frequency rank of both members and their visual similarity.
A4 is recorded at frequency rank #18,471, classified as aname. AD is at rank #1,779, tagged as anadv, pronounced /ˌeɪˈdi/.
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 20250, this pair ranks #432,443 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of A4 vs AD
Shared letters: a. Private to "A4": -. Private to "AD": d.
"A4" · 1 letters · shape V · "AD" · 2 letters · shape VC