Singular usage of ‘they’ is well-established in English, going back centuries. Depending on your exposure to it, you may yourself use it regularly, as I happily do. It’s great having a single word that can refer to individuals whose gender is unclear or unspecified.
However, gender-neutral ‘they’ and its friends ‘them’, ‘their’, and ‘theirs’, do not and likely cannot have the same function as he/him/his/his and she/her/her/hers without major reworking of the language.
That’s because ‘they’ is also, prominently, the third person plural pronoun. That function is arguably more important syntactically than its usage as a gender-neutral or gender-ambiguous singular pronoun.
The collision of the desire for ‘they’ to be singular, and the possibility for it to be plural, leads to ambiguities that don’t exist for ‘he’, ‘she’, et al.
To illustrate the problem, I asked ChatGPT to tell a story about trans woman Sylvia and daughter, Olivia, going on a walk to the grocery store. My prompt indicated use of ‘she/her/etc’ pronouns for Sylvia. I then replaced all uses of ‘she’ that referred to Sylvia with ‘they’, all uses of ‘her’ that referred to Sylvia with ‘them’, etc. See what you think:
Sylvia and Olivia stepped out of their house on a bright, sunny day. Sylvia had a small list of groceries that they needed to get from the store, and they thought it would be nice to take Olivia along for some fresh air and exercise.
As they walked towards the store, Olivia chattered away about her day at school and the latest books she had been reading. Sylvia listened attentively, enjoying the sound of their daughter’s voice and the warmth of the sun on their face.
When they arrived at the store, Sylvia gave Olivia the list and asked her to help them find the items they needed. Olivia eagerly took the list and led her mother through the aisles, pointing out items as they went along.
As they walked back home, Sylvia felt a sense of contentment wash over them. It was moments like these, they thought, that made all the hard work of being a mother worth it. They felt grateful for the time spent with their daughter and for the simple pleasure of going on a walk together.
Simply substituting ‘they’/’them’ is not enough; the possibility of plural ‘they’ alone means ambiguities arise from straightforward replacements.
For example, the first ‘she’ that I replaced with ‘they’ (“groceries that they needed”) could now refer either gender-neutrally to Sylvia, or plurally to Sylvia and Olivia.
This ambiguity wouldn’t arise if, alternately, we replaced ‘she’ with ‘he’, though of course if their were a son present, for example, a need to disambiguate the male referents would come along with it.
But the plural sense of ‘they’ in particular strongly constrains singular usage of the pronoun. For ‘he’ and ‘she’, there is no such ambiguity and so they are much more flexible.
Languages are evolved systems much more than they are products of engineering. It’s easy to think you’ve considered every possible effect of a change when really you haven’t. I would prefer usage of alternative third-person singular pronouns such as ‘zie’ for those whose experience of their own gender doesn’t align with the prevailing categories. Those who adopt ‘they’/’them’ should be aware of the pronoun’s limitations for singular usage. If it’s still adopted, it should be used with care to avoid confusing hearers and readers in contexts where a plural meaning is live in the sentence.
Of course, real people don’t just replace ‘she’ with ‘they’ without adjusting; additional wording would likely come with the change to clarify who’s meant by it. At least, one would hope, though I’ve seen a few examples of glib replacement with no seeming awareness of how confusing the language was becoming.
To the degree that it takes added wording and circumlocutions to convey the same meaning as ‘he’ and ‘she’, ‘they’ is a lesser pronoun for singular usage. It simply hasn’t benefited from centuries of language change yet. For that reason, we should adopt a new non-gendered third person singular pronoun instead, working with the language we have, instead of fighting it.