Let’s have a look at a strange sentence.
My class today was fun.
Which word is “today” modifying?
It’s an adverb, and the verb is “was”, so “today” must be modifying “was”. Easy, right?
Not so fast!
I think the sentence above is trying to say:
The class I had today was fun.
in which case “today” is modifying “had” because otherwise we’d say
My class was fun today.
So if you say “My class today was fun,” you’re either using Chinese syntax (which requires adverbs to go in front of verbs) to say that your class was fun today, or you’re using the word “today” to modify a verb that’s not technically even in the sentence but buried inside a possessive adjective.
You could say “Today’s class was fun,” using “today” as a noun but transforming it into a possessive adjective; then you’d be missing “my”.
In Chinese, I believe you could say “My today’s class was fun” because apparently there’s no rule against doubling up demonstratives like that; I’ve heard people say things like “my the other one is nicer”. In English.
In Singapore maybe you could also get away with “My today class was fun.” After all, “today” is an adjective on all the signs outside restaurants that say “Today Special”. Such signs are of course attempting to say “Today’s Specials”, but they not only fail to transform the noun “today” into a possessive adjective, they also fail to pluralize “special”, an adjective acting like a noun.
Why do we even have different parts of speech? Words change part of speech constantly, and people “misuse” them, and start fights about whether they are in fact misusing them or not, and yet we all manage to understand each other anyway. Most of the time.
Maybe the concept of parts of speech survives for entertainment value—and to provide jobs for English teachers!
Speaking of which, back when I was a teacher for a company called I Can Read, I posted about using “I can…” to test whether a word is a verb. The word ‘window’ hilariously failed my test.
Or so I thought. Shakespeare would disagree.
Antony and Cleopatra (IV.xiv.72):
“Wouldst thou be windowed in great Rome…?”