In the original US release of Chrono Trigger, the character Frog was translated to speak Early Modern English. (Often called “Old English” in online discussions, but it’s obvious what people mean.) In the DS retranslation many years later, it was changed to modern English.
You can find innumerable discussions online about which is better. There tend to be 3 arguments against:
He doesn’t talk in an overly polite or antiquated way in Japanese, so it’s unfaithful to the script.
Nobody else in the time period talks like that, so it makes no sense for him to.
In flashbacks from before he’s turned into a frog, he doesn’t talk like that.
The arguments in favor tend to be in the form:
It gives him more personality.
People like what they grew up with.
No need to rehash those discussions here. As someone who also grew up with EME Frog, I’m kind of partial to the idea. I’d like it if everyone in the 600 AD time period spoke EME.
But there’s a problem that keeps me from enjoying it. Frog does not speak Early Modern English. He speaks Ye Olde Butcherede Englishe, and sounds like an idiot.
I’ll show you what I mean. I played through the game using Frog at every opportunity, sometimes replaying cutscenes with him in different party positions. This isn’t a complete script capture, but it’s enough to be representative.
But first, some quick tricks for understanding Early Modern English rules. You can usually make modern English substitutions.
The th/eth verb ending is the same as the modern English s/es verb ending, used for third person singular subjects. Simply replace with an s.
The t/st/est verb ending doesn’t have any shortcuts for modern English understanding, but it follows an easy rule. If the subject is anything other than “thou,” it’s wrong.
Replace thou with I, he, or she. Replace thee with me, him, or her. If the result sounds silly in modern English, then the original sounds silly in EME.
Replace thy or my with a. Replace thine or mine (as possessive determiners) with an. You might have to change the modified noun to singular.
I’ll review only those dialogue boxes that contain one of the above and rate with an X if wrong or O if correct. I’ll caption with the above substitutions so you can see how they sound. I’m leaving out Frogisms like ‘tis, ‘pon, ne’er, etc. Those are used correctly throughout the game.
We begin with Frog rescuing us from a Naga-ette monster.

“An guard.” X
Well, that’s a bad start. At least it got “thou art” right. The conversation continues.

t verb ending, subject is “thou.” O

“Will him accompany me?” X

“A guise does not incur a trust.” O

“Do as me please.” X
Frog doesn’t consistently use Early Modern English grammar. Sometimes the grammar is modern but the vocabulary is antiquated:

In EME it would be, “Mayhap a hidden door lurketh nigh?” I’m not counting these as errors. Shakespeare also used both sets of rules, sometimes within the same sentence. It’s not unusual for them to be mixed a bit.

“I thank him.” O

“I has disgraced him.” X

“You has potential.” X
We next encounter Frog when we revisit 600 AD to help in the war against Magus. In Frog’s home:

“It’s me.” t verb ending, subject is “thou.” “A skill.” O
Regarding the above, I remember being taught in school that if you use the verb “is,” the predicate has to be in the nominative case rather than oblique. (That is, you must say “It is she” rather than “It is her.”) There’s a joke in The Venture Brothers about this:
If you can’t be bothered to watch, Henchman 24 says, “Is this them?” Henchman 21 corrects, “Are these they?” 24 responds, “Who talks like that!?”
Anyway, my middle school teacher was wrong. Both “it is I” and “it is me” are grammatical and have been used for hundreds of years. The former is more formal than the latter. Frog’s “‘Tis thee” is fine.

st verb ending but subject isn’t “thou.” X

st verb ending but subject isn’t “thou.” X

“Me has returned?” X

The first st verb has “thou” as the subject, but the second has “I.” X
One could argue that Frog isn’t supposed to be speaking EME. That it’s a fantasy world, and it’s fine for an in-game language to have different rules. The problem is, from examples like the above, it’s clear that it doesn’t just have different rules. It has no rules, no consistency. These dialogue boxes are right next to each other, but the game can’t make up its mind whether it’s “thee hath” or “thou hast.”
You throw in “st” or “th” when you want something to sound old-timey. Choose whichever one you’re vibing with in the moment. That’s the only rule there is.

“Nary a soul remains to mend’s the Masamune.” X

“It’s me again.” O

“Remain’s here the night.” X
That last one could be grammatical if “night” were the subject, except for the misplaced apostrophe. Alas, it’s supposed to be an imperative to Crono and pals.

“10 years has passed.” ~
I’m calling that one ambiguous. Normally you’d say “10 years have passed” but people sometimes treat a plural group of things as a singular subject. (As in, “Is this them?”) So it’s not egregious.

“Awake’s, Crono!” X

st verb ending, subject is “thou.” O

“Hand’s over the Masamune!” X

“An name.” X

“I has heard only magicians wield it now.” X

st verb ending, subject is “thou.” The apostrophe is misplaced, but I’m judging grammar errors here, not punctuation. O

“A time has comes, Ozzie.” X
That last one reminds me of the way young children speak. They often don’t understand that if you inflect an auxiliary verb, you don’t always have to inflect the main verb. So they say things like “did napped.”

“I owes it all to you!” X

“We has lost him…” X
This ends Frog’s part of the story, save for a side quest at the end. You never have to use him again. So far we’re at a 72% incorrect rate.

st verb ending, subject is “thou.” O

“An quest.” X

“I will not allow him to meet a demise.” O

“I refuses to be party.” X

“Lavos has fallen.” O

t verb ending, subject isn’t “thou.” X

“I knows not what this portends.” X

“What does challenge us?” O

t verb ending, subject isn’t “thou.” X

“An name.” X

“An head.” “You has fixed.” X
In some English words, like “hour,” the h is unpronounced. It used to be that way for almost all English words beginning with h. Once upon a time, “an/thine head” would have been correct. But the verb is wrong in the second sentence, so it’s still an X.

“We won’t allow him.” O

t verb ending, subject is “thou.” O

t verb ending, subject is “thou.” O

“Where has she gone?” O

“Something comes.” O

That one isn’t EME, it just cracks me up that Frog also employs a random Britishism.
At this point in the game, you can choose to fight Magus or not. I did both for the screenshots.

t verb ending, subject is “thou.” O

t verb ending, subject is “thou.” O
As a kid, I liked to use Frog. The first time I played through, this plot point went over my head. If you have other characters in the lead, they say, “You’re Janus” explicitly. But Frog refers to a line he said before, about Janus being an urchin.
Anyway, it’s fine. The game shows all you need to put it together. Sometimes kids are dumb and even obvious plot points go over their heads ¯\_(ツ)_/¯
If you fight him:

“A tongue.” O

“I has avenged him!” X
If you don’t fight him:

“Vanquishing him will neither…” O
Amusingly, now that Frog’s optional and we’re not focusing on his character properly, the last stretch helped his pass rate substantially! Now we’re at only 57% incorrect.

“The Ocean Palace has risen? Surely, it does beckon us!” O

“By a leave, mayhap we takes this doll?” The “thy” is right, the verb isn’t. X

This has nothing to do with Frog, I’ve just always found it funny that the bottom part of the Lavos Spawn shell appears at the top of the screen here.

“Me who fear’s the night and stand against the darkness.” X
Come on, even people who don’t know EME can tell that last one sounds ridiculous, right?
If you say “X who Y and Z,” where X is a pronoun and Y and Z are verbs, both Y and Z have to be inflected the same way, based on X. Here, they’re both inflected two different ways—and neither of them are right for the pronoun! And the pronoun isn’t the right case! This is probably Frog’s worst line in the game.

“To has travelled so far.” X

“Crono! Gives an answer!” X

t verb ending, subject is “thou.” O

“A friend.” O
We’re in the final stretch. I’ll knock out Frog’s side quest first. Since I’m stuck using him, I might as well power him up ASAP.

“My sword has no effect!” O

“I has returned.” X

“My promise to him.” O

“He must think ill.” O
Moving on to other side quests:

“THEY changes the forest.” X

“How to slays monsters.” X

“Before death claims them.” O

“Lavos plays an integral role.” O

“We asks a favor.” X

“Thanks to him.” O

“But it lacks luster.” O

t verb ending, subject is not “thou.” X

t verb ending, subject is “thou.” “History has been changed.” O

That one has nothing to do with Frog. I’m just astonished that, in so many years playing this game, I never noticed that Melchior says, “This is a very rare!”
In any case, I wrapped up all the side quests. For the most part, Frog doesn’t use the EME constructions in question, in what little dialogue he has. So let’s jump to the ending. If you go through the Black Omen or the bucket at the End of Time, Frog doesn’t use any EME before or after entering Lavos’s shell. If you go through the Epoch, he does. But only in one party position.

“Be him certain?” X

“This battle leads nowhere.” O

“We haves no choice!” X
Before facing Lavos’s second and third forms, characters will give a little speech. Frog doesn’t say anything interesting before the 2nd, but he does before the 3rd.

“Our lives has been for naught.” X

“My life retain’s its meaning!” O, despite punctuation.

“We haves our own will!” X
“Haveth”?
…

He’s been using “hath” the whole game. Here he seems to forget it exists—not that it’s the right word to use anyway. Woolsey conjugated it correctly (“have”), then threw a random “th” on the end of it. I vote this as Frog’s second most ridiculous line. And it’s the last thing he says before the ending.
Anyway, the ending! Of course there are multiple, and I’m not going to go to each of them just to determine if Frog has any lines in them. I’ll just show the standard ending you get if you fight Lavos after reviving Crono.
So here we go. It’s the ending. Big, emotional moment. Will the game stick it?

“An time.” X

“An kin.” X
No. Frog has 4 lines in this ending. 2 of them use the EME constructions in question, and they’re both wrong.
Our final tally is 55% incorrect. Those optional lines helped substantially. If you were to never use Frog again after fighting Magus (except for finishing his side quest & the mandatory lines in the Fiona quest around the campfire), it would be 64% incorrect.
Granted, this is only a fraction of Frog’s total lines in the game. I tallied up 74 here (ignoring the ambiguous one). But I took 215 screenshots. Using that as the denominator, 19% of his dialogue boxes are ungrammatical. (I skipped a few that were nothing but “???” or the like.)
To be clear, I love this game. A lot. A lot. Playing through it again has been wonderful and I learned some stuff I didn’t know about before. None of this keeps me from enjoying it, and for people who don’t have an ear for EME, it doesn’t even matter. But if you do have an ear for Early Modern English at all, then it’s hard to prefer EME-speaking Frog. He doesn’t sounds like a respectable, noble swordsman. He sounds like a child who’s learning how to talk.
On the bright side, if you choose not to use him because of this, it’s not like you’re missing out. He’s one of the worst characters. Sorry not sorry.