# their vs thesis

> English confusable word pair

## The two words

### their
*determiner · IPA /ðɛə/ · frequency rank #56*
Belonging to, from, of, or relating to, them (plural).

### thesis
*noun · IPA /ˈθiːsɪs/ · frequency rank #6,636*
Senses relating to logic, rhetoric, etc.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/vs/their-vs-thesis