# sei vs sein

> Spanish confusable word pair

## The two words

### sei
*num · IPA /s̺ej/ · frequency rank #48,072*
Seis.

### sein
*verb · IPA [ˈzaɪ̯n] · frequency rank #45,601*
Ser, estar.

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