Those are the people that don't understand that "can" and "can't" in this context is just a matter of definition. If you want to try to slow the process of lan

Those are the people that don't understand that "can" and "can't" in this context is just a matter of definition. If you want to try to slow the process of language change in order to make it easier for more people to communicate with each other in English for a longer length of time before English dialects diverge into mutually unintelligible languages, it makes sense to create one official dialect of English with prescribed rules and try to get authors to follow it, a la Strunk & White or almost all dictionaries besides the OED (the OED takes a descriptivist approach to definitions based on how people actually use English). However, the existence of standardization efforts should't mean that people are somehow speaking their native dialects "incorrectly." The fact that some prescriptivist decided not to include the singular "they" in his or her artificial dialect of standardized English doesn't make the singular "they" any more "wrong" in my idiolect of English than the existence of the RnRS standard would make other dialects of Scheme like Racket "wrong," regardless of how one defines "wrong" as long as its definition is held constant. In the same way, every English speaker alive today could be said to be speaking "grammatically incorrect" Old English or Proto-Germanic (an even older language that refers to whatever language existed way back in the day that all modern Germanic languages descend from), but there's no point in making a statement like this. That's why virtually all linguists take a descriptive approach to language and describe anything grammatical (as opposed to the phrase "grammatically correct" which would endorse the existence of a "right" and "wrong") if it sounds natural to native speakers. Unlike some linguists who love to see language change, I'm fine with people prescribing a standard and sticking to it for most written works, as long as they realize that it's just a standard and not some divine definition of "right" and "wrong." So feel free to use the singular "they" rather than artificial alternatives! Note: Some far left scholars of gender studies demand the adoption of artificial gender-neutral pronouns (as opposed to using the singular "they") for a very different purpose--to make transgendered and intersexed people no longer "oppressed" by the English language. That is, if you already know the person you're talking about, all natural dialects of English involve saying "he" or "she" did blablabla. However, if someone identifies their gender (haha doesn't that sound so much more natural than "his or her gender"?) as something other than male or female, current English runs into a problem. Such scholars often propose "zhe" and "zher" for subject and object/possessive. But here we are just discussing situations when you are referring to an individual (i.e. a programmer or "someone" in the case above where I used the natural sounding "their") whose gender is unknown. This usage of the singular "they" happens to cover transgendered people as well.