[T-Bone Texan]

I sat octopi. Is that wrong?

Because I also say penii, and that is definitely wrong.

[NativeSon]

I am in no way, a spelling or grammer expert- this just stuck in my head after reading it a lifetime ago.

As octopus is a Greek word, the plural is made by adding "es", not "i".

Also, I have in the past, tried to convince a number of people that the plural of 'dolphin' is 'dolphi'...