"I mostly remember it but it'd be easy to get lost and I don't have proof positive that I can actually work the grace song on myself..."
That's an impressive trick. Well, assuming it's all posture and no telepathy. Kib nibbles on things; it might be a while before Fëanáro doesn't-break-for-food.
"Is it common to refer to twins with a plural like that? Just because they were born at the same time?"
"How do people in your world get named? Here the mother picks a name and the father picks a name and the child selects which to go by, or can go by yet a third if they want. My mothername is Maitimo and my fathername is Nelyafinwë, which is why people who aren't my family will refer to me as Prince Nelyafinwë."
"We get usually two names from whoever's got a name idea they want to use at the creche. They try to avoid overuse and strictly avoid duplicate combinations - I know another Akibel but not another Akibel Mowar, and she goes by the feminine nickname Aki, not Kib, my creche was kind of mad about unisex names. We can go by either one but the first one's typical, as are shortenings. Some names are more common than others - there's a creche downtown where every year they name somebody after the first governor of our city-state, other names get made up - especially if they mean something in the vernacular, people go around being called 'Nutmeg' or whatever - or revived after falling into obscurity - 'Alymbel'."
"Your accent's not bad, some other people have been tripped up when I introduced myself."
"The Valar speak Valarin but no one's been able to learn it but my father. The Vanyar say they speak Quenya and we speak a confused dialect of Quenya but we say it's the other way around, and call theirs Quendya. Telerin is mutually intelligible but quite different. And then there's the language that only very old people speak that we had in the Outer Lands."
"There's tons of languages at home. The common's catching on more and more around where I'm from, creches are no longer making a point of teaching people more niche languages and it's not typical to bother picking one up on purpose."