cactii or cactuses

[sirfredfredgeorge]

So DD was playing on some phonicsplay game - www.phonicsplay.co.uk/PondLifePlurals.html - no idea why, apparently they did an ibb and obb game in school, so she looked it up on her computer, and found the above game)

She was doing surprisingly well considering she's 4 and in YR, but then got annoyed because it said cactuses was wrong as a plural of cactus - it had to be cacti. I would've said both are okay, cacti being one of the latin originated words you can pluralise that way, but I certainly wouldn't've said cactuses was wrong.

Is this just a feature of the game, or would cactuses really be considered wrong?

Both are right. There are a zillion examples of other Latin 'us' words (or second declension nouns if you're getting technical) which have anglicised 'uses' endings. So there's already a precedent and a convention there.

If I was being super picky, the root of the word cactus is Greek originally, not Latin, so in that case an 'I' ending would be more appropriate.

But essentially, either is fine.

I would have said cacti was right and cactuses is wrong (autocorrect doesn't like it either) but I've learned something new thanks to WhatsYourDamage.