No one has ever used the Italian singular of that word in English. As a loan word, it does not have to follow Italian grammar rules, and similar to pasta, it can be used both as countable and uncountable (i.e. a generic category term without plural).
Of course it is. What kind of argument would I have if it weren’t?
But the singular was never used in the tweet.
“what calamari is”, two times.
No one has ever used the Italian singular of that word in English. As a loan word, it does not have to follow Italian grammar rules, and similar to pasta, it can be used both as countable and uncountable (i.e. a generic category term without plural).