used when the subject of the verb is "they" used as a singular pronoun, or a single person who could be any gender, and the object is the same person

It's all about letting someone be themself. 最重要的就是让一个人做真实的自己。

Our publication uses singular "they" and "them" when discussing a nonbinary, agender or gender-fluid person who uses those pronouns for themself.

used for emphasis when the subject is "they" used as a singular pronoun, or a single person who could be any gender

Each parent/child relationship is different and the only expert on that specific child is the parent themself. 每名父亲或母亲与孩子的关系都是不同的，对于某个特定的孩子，唯一的专家就是这名父亲或母亲自己。