Which to use
“their” is a determiner and “third” is an adjective - they look or sound alike but fill different roles in a sentence.
- #56
- “their” frequency rank
- #483
- “third” frequency rank
- 539
- confusion score
Side-by-Side Comparison
| Feature | their | third |
|---|---|---|
| Definition | Belonging to, from, of, or relating to, them (plural). | The ordinal form of the cardinal number three; Coming after the second. |
Where the eye mixes their and third
Muted = shared; highlighted = the visual trap. They share 4 letters in sequence.
Spelling & Dictionary Insight
These two trip readers on the page rather than in the ear: their is /ðɛə/ while third is /θɜːd/. Spoken aloud the problem disappears. In writing it persists, because they share most of their letters but differ in 3 positions, and the parts of speech differ too (determiner vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 539, derived from the frequency rank of both members and their visual similarity.
their is recorded at frequency rank #56, classified as adet, pronounced /ðɛə/. third is at rank #483, tagged as anadj, pronounced /θɜːd/.
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 539, this pair ranks #529,244 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of their vs third
Shared letters: hirt. Private to "their": e. Private to "third": d.
"their" · 5 letters · shape CCVVC · "third" · 5 letters · shape CCVCC