Comment by sowbug
12 hours ago
The first two of the three are adjectives, each connected to the subject by the one "is," and the third is a verb phrase not using the "is." Ideally they'd be all adjectives using the "is," or all phrases supplying their own verbs.
Not the worst error in the world, but it stands out in LLM text that is otherwise remarkably nit-free.
But is it even an error? You are parsing it as a single list, but it could just as well be parsed as "subj ((is {a,b}) and vp-predicate)".
I guess you could argue that the first list needs an "and"? That's fair I suppose.
(We have descended into one of the deeper circles of grammar hell. I will remind you that you're free to leave at any time.)
Yes, exactly. English grammar actually doesn't require the "and" to end a list (leaving it out is called "asyndeton" if you're curious). A good example is Lincoln's Gettysburg Address: "... and that government of the people, by the people, for the people, shall not perish from the earth."
So after all this, there actually is a way to analyze the example that is strictly valid. But most people would look askance at the standalone sentence "This product is fast, lightweight." That is, I suppose, unless someone like Abraham Lincoln worked it into his next speech.