[Petrosius]

“Somebody left their his umbrella in the office. Could you please let them him know where they him can get it?”

“My personal rule is to never trust anyone who says that they he had a good time in high school.”

“The patient should be told at the outset how much they he (or "she" as required) will be required to pay.”

“But a journalists should not be forced to reveal their sources.”

But don't trust me. I had a good time in high school.

[Jamestown1630]

You’re using the generic masculine.

(But your spelling and grammar need some work here and there:)