I am new here and I don't really know how to post, so please forgive my mistakes. My question is this: Is a sentence like "everybody has to obey their own parents" nowadays completely acceptable under a grammatical point of view or it is still preferable, in written form, to use "everybody has to obey his/her own parents"? Thank you very much and sorry if this has been asked before.
This has indeed been asked before — so many times, in fact, that the question is in our all-time Top 40 (and a closely related one in the Top 3, even). One of the many duplicates is the third result when searching the site for "their". Please do use the site search and the frequently asked questions tab in the future. It saves us work and gets you your answer much faster. Thank you.– RegDwigнtJan 29, 2014 at 11:38
Thank you very much RegDwight and my apologies. The links you provided in your comment proved themselves vital for me to learn how to use this forum correctly.– chipulukusuJan 29, 2014 at 12:51
As has been confirmed here in the discussion of previous posts, it is perfectly alright to use 'their' as a singular pronoun. This is especially helpful when you either do not know the gender of the person, or where something is written to people in general, as this is. The 'singular their' has a long and honourable history in English.
It is grammatical now, and always has been.