MemriseForgiveTypos.user.js

Shows an alert box once if the Levenshtein distance of a given answer and the correct answer is 1 or 2.

I'm not a big fan of making a hack like this but at the same time I don't think you should be punished for accidental typos as Memrise currently does. Use at your own peril.

Installation

I have tested the userscript on Chrome and Firefox using Greasemonkey.

Firefox

1. Install Greasemonkey.
2. Go to http://userscripts.org/scripts/show/167003 and click Install.

Chrome

Method 1 (Recommended)

This method provides automatic updates for the script.

1. Install Tampermonkey extension on Chrome Store.
2. Go to http://userscripts.org/scripts/source/167003.user.js and click OK to confirm installation.

Method 2

1. Download MemriseForgiveTypos.user.js to your computer.
2. Go to the extension view in Chrome (chrome://extensions).
3. Drag the MemriseForgiveTypos.user.js file on the extension page. It should say "Drop to install" as you do so.

Safari

I haven't tried. Search Google for ways to install userscripts.