I've been perplexed by a certain usage of the uninflected verb, and see it quite often. For example, I happened upon the following passage in reading on the pre-war South: "If a white person assemble with Negroes for the purpose of instructing them to read or write, he shall be confined to jail not exceeding six months and fined not exceeding one hundred dollars" –– Virginia. Code [1848], 747-48 In the first sentence, why is the verb "assemble" unconjugated or invariant? Rather than, "If a white person assembles with... Or in a second example, which I pulled off a sports forum today (at realgm.com about a Knick basketball player, if you're curious): No shirtless pics, I am disappoint. Why is it not as follows?: "No shirtless pics, I am disappointed." What is the specific grammatical rule (or rules) governing this?
The grammar rules are that the two examples you have found are errors! This one looks like a simple typographical or typeset error. The S was simply missed. This one may just be either a netspeak abbreviation or someone trying to be cute with 'charmingly broken' English. Regardless, they are both errors.
The first one might also be an archaism. It resembles subjunctive voice, but without an auxilliary verb/
It does resemble the subjunctive, to be sure, missing the were to. And there are archaic subjunctives that obviate syntax we consider mandatory in today's English: I will not let thee go, except thou bless me. (King James Bible, Genesis 32:26) The that is achingly missing in that construction to modern eyes. But I could not find an example that obviates the auxiliary verb. Doesn't mean it doesn't exist, just that I couldn't find it.
'I am disappoint' is net speak. It isn't proper, but it appeared as a meme early last year (EDIT: Early 2008, actually :/ ) and kind of stuck. http://knowyourmeme.com/memes/son-i-am-disappoint Also, on most forums, it isn't a good idea to take people's grammar as correct lol
the first form was correct in its day... just no longer in use... the second is nothing but a mistake... either by someone whose first language is not english, or a lazy net-writer... if it's become common usage, that's just another reason to bemoan the advent of netspeak!
