Although we generally say something like “the fifth of November” or “April the seventeenth” (or variants depending on US/UK etc.), it’s not normal to write it out that way.
Singular subjects require singular verbs and plural subjects require plural verbs… except when they don’t.
A singular noun. Yes, the origin of the word is the Latin plural of datum, but that’s not the point. Languages are dynamic and changing; if you don’t go with the flow, it can sound hypercorrect.
Modern English is increasingly gender-neutral. Efforts to render forms of address such as “mw. mr.” too literally come out as confusing or plain laughable. Professions and roles in which the person’s gender is irrelevant don’t need to be gendered.
One no longer uses the indefinite third person singular, as the grammarians like to call it. Unless one is called Prince Charles.