The story of the number zero is old and interesting and important, but this post is about the zero that's to do with language.
Zero is actually a really easy idea: a zero feature is one that's usually, or often, or could be, used - but isn't.
One word that's is optional a lot of the time is that. So, you can write (or say) she said she'd be honest with me, without bothering with the that of she'd said that she'd be honest with me. That's a zero that-clause.
But grammatical zero isn't always so, well, grammatical. Someone might say You ready? Instead of Are you ready? for instance, and this kind of thing is often a feature of a dialect. British people go to hospital; people in the USA go to the hospital. Some other dialects won't bother much, for instance, with plural forms: give me three banana. (You can also count the plural s missing at the end of a word like moose as a zero feature, in the same way.)
And what's the plural form of the English indefinite article, otherwise known as a (as in a cow)?
That really is zero.
There are also zero aspects of language that change the meaning of a sentence. I like horses in the countryside means something different from I like the horses in the countryside.
Altogether, it's amazing what an absence can do.
So [you] enjoy omitting words, now, okay?
Nuts and Bolts: zero. This word came to English in the 1600s from Italian, from the Latin zephirum, from Arabic sifr, empty.