Which to use
“1d” is a noun and “1st” is an adjective - they look or sound alike but fill different roles in a sentence.
- #25,647
- “1d” frequency rank
- #1,549
- “1st” frequency rank
- 27196
- confusion score
Side-by-Side Comparison
| Feature | 1d | 1st |
|---|---|---|
| Definition | Abbreviation of one penny (a coin with the value of 1 pence/penny; 1/240th of a pound, in pre-decimalisation currency, never used for 'one new penny'). | Abbreviation of first. |
Where the spellings diverge
Shared letters are muted; the letters that actually set 1d and 1st apart are highlighted. They share 1 letter in sequence, which is exactly why the eye skips the difference.
Spelling & Dictionary Insight
Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: 1d is anoun and 1stanadjective. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 27196, derived from the frequency rank of both members and their visual similarity.
1d is recorded at frequency rank #25,647, classified as anoun. 1st is at rank #1,549, tagged as anadj, pronounced /fɝst/.
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 27196, this pair ranks #380,812 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of 1d vs 1st
Shared letters: none. Private to "1d": d. Private to "1st": st.
"1d" · 1 letters · shape C · "1st" · 2 letters · shape CC
Frequency comparison
Frequently Asked Questions
Can "1d" and "1st" be used interchangeably?
Which is more common, "1d" or "1st"?
Remembering 1d vs 1st
The fastest way to pick the right one every time.
- Check the role first: if you need a noun, it's “1d”; for an adjective, it's “1st”.
- See each word in full, definition, IPA, etymology and its other confusables. Full “1d” entry
- Browse more pairs most likely to be confused. Most confusable