[quote=@Unlucky0013]
<Snipped quote by Diggerton>

-.- for one person? 
[/quote]

Yeah, they/their is perfectly acceptable for one person. If you were to use the sentence 'He took out his trash' how would you say it if you didn't know *their* gender? 'They took out their trash'.


https://en.wikipedia.org/wiki/Singular_they