# A4 vs ai

> English confusable word pair

## The two words

### A4
*name · frequency rank #18,471*
A4 class, a class of steam locomotive used on the London and North Eastern Railway.

### ai
*noun · IPA /ˈɑ.i/ · frequency rank #4,818*
A type of three-toed sloth, Bradypus tridactylus, endemic to forests of southern Venezuela, the Guianas, and northern Brazil.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-09-02.
Canonical page: https://plainspell.com/en/vs/a4-vs-ai