What does “distributional” mean in grammar?

Question

I'm reading an article on Syntactic Categories and came across the following heading:

Syntactic categories are distributional not semantic

I believe the "syntactic categories" the author is referring to are parts of speech:

Noun
Verb
Participle
Article
Pronoun
Preposition
Adverb
Conjunction

I want to understand what the author means when she says the categories are "distributional".

At first, I was hung up on the distinction between the two words:

Syntax
Semantic

I came across another answer that helped me out:

In summary, syntax is the concept that concerns itself only whether or not the sentence is valid for the grammar of the language. Semantics is about whether or not the sentence has a valid meaning.

So in Plain English it seems the title is trying to say:

"Parts of speech are _______ but actually don't convey meaning."

The author uses the word "distributional" again later in the second paragraph as an adjective to describe the noun "properties" as in "distributional properties".

The questions

• What does it mean for a part of speech to be distributional?
• What are distributional properties?

Answer 1

Distributional refers to the distribution of words in utterances. Where they go, where they don't.

Different types of word is what syntactic categories means. You may have learned the concept as "parts of speech". The list you give is different from the list in the article, so let's ignore that.

The point is that whether a word is called a noun or a complementizer or a preposition depends not on what it means (that's semantic, i.e, meaning), but on how it's used (that's syntactic, i.e, grammar). For instance, rock is a noun in the first sentence below, but a verb in the second:

• An earthquake could shift the rock down the hill.
• An earthquake could rock the stone down the hill.

Very few words in English are intrinsically only one part of speech, and those that are are mostly function words like the and not, which are part of the machinery of grammar, and don't really have lexical meanings like rock or shift.

Definitions of noun like 'person, place, or thing' are not distributional, but semantic, because they refer to what a noun can mean. And semantic definitions of grammatical terms are unsatisfactory; they don't work -- truth and liberty are clearly nouns, but are they people, places, or things?

Distributionally, if a word in English can be modified by an article, for instance, it's a noun;
if it can be put in the past tense, it's a verb. And so on. There are tests you can make.
That's all, really.