#1.
If you’re talking about arguments between celebs on Twitter, then those are beefs, FYI.
#2.
An opera is more than one opus. Who knew?
#3.
Though “sphinxes” is also acceptable.
#4.
It’s literally translated from the Latin for “two-headed” because each of your biceps connects to the upper arm via two heads.
#5.
In French, it means “bottom of a sack”, so if it’s plural, it’s “bottoms of a sack”. That’s a lot of bottom.
#6.
It was only coined in 1951 and we don’t want this word to disappear.
#7.
Same with mothers-in-law, fathers-in-law, postmasters general and the like.
#8.
You might mistake it with “octopi”. Octopi is actually a Latin plural word, while “octopus” is Greek.
#9.
So technically, you should be ordering lasagne from the bistro.
#10.
Prius is actually a Latin word meaning “first” or “original”, or “superior”. It was Toyota who officially announced that “Prii” is the new plural word after more than 1.8 million people voted for it in 2011.
#11.
Did we confuse you? Plankton is indeed its plural form, we just flipped the script a bit.
#12.
Similarly, (and awesomely) the singular form of confetti is one piece of confetto, same goes with graffiti — it’s graffito.