Nobody would ever say "Ĝi frapis Sara-on". It isn't even an option. If it ends with a vowel, you don't add the -on. You just add -n.

But if the name ends in a consonant, some people might add -on. "Oni frapis Ĉang-on"

But normally if a name ends in a consonant, we don't bother adding -n. We woudl just say "Ĝi frapis Ĉang". We know that Ĉang is the direct object because "ĝi" lacks -n. And at any rate if it were "Sang frapas Ĉang", two names not ending in a vowel, then standard word order would tell us that Sang is the subject and Ĉang is the object.

Would "sang, li frapas ĉang" work?

It would only work insofar as you'd ever want to say "Sang, he hit Chang" in English.

It might come out in colloquial speech but it wouldn't be a normal way and you definitely wouldn't word it that way to avoid the accusative.

This is where standard word order comes in. This situation is a non-issue as far as Esperanto is concerned. It's a basic principle that word order is flexible, but that we don't make use of that flexible word order in cases where it would interfere with correct understanding of the sentence.

tommjames:If the name ends with a vowel it's also possible to just tack the "n" on the end, so "Iu frapis Saran", like from PMEG: "Ĉu vi konas Annan?"

erinja:Nobody would ever say "Ĝi frapis Sara-on". It isn't even an option. If it ends with a vowel, you don't add the -on. You just add -n.

Thanks to both of you! This is what I love about LERNU - the newbie (Lyle, welcome!) asks his question, and I learn/re-learn two new/forgotten things.

I suppose I do have one more question. I was trying to figure out the spelling of some of my friend's names and I realized there does not seem to be an equivalent to "th" or 'i' as used in ship. So what do you do with names using those sounds?

th is usually simplified to t. The i like in ship is normally simply pronounced as ee like in steel.

This is part of the reason why we tend to Esperantize names. If you're going to mangle my name Erin (American R, short I) as "Eh-rrrr-een", then you might as well go all the way and add an -o to the end.

American English uses a lot of schwa vowel sounds. That's actually the more difficult case, because you have to decide which vowel to pick. Let's say you wanted to esperantize the English name Sully. How do you render that? "Suli" would be "soo-lee" if you translate the letters strictly, which doesn't sound much like Sully at all. You could go with "sali" (sah-lee)but that also isn't super close. And once you're that far from the original name, you might as well go all the way and call yourself "Sulio" or "Salio" or "Selio".

Anyway, many names with the th sound have international versions that lack that sound, so your name may actually be MORE understandable to foreigners without the th.

Jonathan = Jonatano (from the Hebrew "Yonatan")
Elizabeth = Elizabeto (from the Greek Elisabet, which is from the original Hebrew Elisheva)

Of course if we're talking about a name like Keith, it probably doesn't have an international version, in which case foreigners will find your name totally unfamiliar (and probably not even sure if it's a man's or a woman's name) so you would be doing them a huge favor to simplify the sounds down to "Kito" or something.

I speak from some amount of experience here. I never thought the name "Erin" was that hard until I did some international travel and people weren't sure if it was a man's or a woman's name, and I was often asked to repeat my name, only slower, so people could figure it out. That's even with my simplified-for-foreigners "eh-reen" pronunciation, not the full-on American R and de-emphasized short i.