# aching vs actin

> English confusable word pair

## The two words

### aching
*verb · IPA /ˈeɪ.kɪŋ/ · frequency rank #19,750*
present participle and gerund of ache

### actin
*noun · IPA /ˈæktɪn/ · frequency rank #24,076*
A globular structural protein that polymerizes in a helical fashion to form an actin filament (or microfilament).

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