[lupire]

There's no reason to assume that an human word begins and ends with a space. Compound words exist. The existence of both "Aforementioned" and "previously spoken of" isn't based on a deep neurological construct of compound words.

[mcswell]

Sorry, I'm not following. What do spaces have to do with this? Grammar is dependent on concepts like lexemes (sort of like words), but there aren't any spaces between lexemes in spoken language.

[Izkata]

Probably slight confusion over the description, which I was thinking at first with the first "in the middle of" example - that English has compounds nouns so the existence of spaces doesn't necessarily work as a delimiter.

What it seems to be getting at instead is that language works more like madlibs than previously thought, just on a smaller scale than madlibs. Which to me isn't that surprising - it seems extremely close to "set phrases", and is explicitly how we learn language in a structured way when not immersed in it.

I also suspect most people don't even know about tree-style sentence mapping. I've mentioned it a handful of times at work when languages come up and even after describing it no one knew what I was talking about. I only remember it being covered in one class in middle school.

[mcswell]

I had to look up 'madlibs', but I see now what you mean. We do indeed have lots of canned phrases, some of which are idioms. They may indeed come with blanks at the end (your example) or even in the middle ("pull __'s leg"). The issue I have with the original paper is that these canned phrases need to fit in with the language's overall grammar, e.g. "What did the fire alarm come in the middle of __?"

"Tree-style sentence mapping": I assume you mean the old sentence diagramming where the main part (more or less) of the sentence was on a line, and adjuncts (like prepositional phrases) were shown as branching off the bottom of the line on a diagonal. But there are also tree diagrams of the sort made popular by Chomsky and the generativists who followed. In fact I was once employed doing more or less that, just before the AI bubble in the late 80s. Fun!