# past vs PSP

> English confusable word pair

## The two words

### past
*noun · IPA /pɑːst/ · frequency rank #437*
The period of time that has already happened, in contrast to the present and the future.

### PSP
*noun · frequency rank #21,627*
Initialism of phenolsulfonphthalein.

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