Papahl’s text got edited slightly between E GB/C and E Switch to avoid repetition created by the icons. Also, in Japanese, he doesn’t say anything about not intending the hibiscus to be a reward, just “Oh yeah, about your reward…”
On Switch, he gets an extra line thanking Link. On GB/C he just repeats the “Delicious!” line.
In Japanese, Write says that Christine sent him a bromide, a kind of celebrity photo meant to be collected by fans. On GB/C she signs her name on the photo, but on Switch it’s just a hoof-print.
When refusing to give Grandma Yahoo the broom, her response in English is a little more forceful. In Japanese, she says (roughly) “Oh dear… Then are you going to clean the island?”
In Japanese, Grandma Yahoo only says that she picked the fishhook up by the river. She doesn’t specify whether she was sweeping there, though the English assumes she most likely was.
Christine gets some nice little puns in English when talking to her after delivering the letter (“Baaa-vo” and “kidding”). These lines are new as of Switch.
On J GB/C the mermaid has lost her swimsuit, but on E GB/C this was revised to a necklace. On Switch, both English and Japanese refer to a necklace. But in Japanese she still teasingly says “I’ll give you my XXX!” instead of directly saying she’ll give you a scale, as the English does.
On J GB/C if you dive by her, she’ll call you a pervert and swim away. On E GB/C she’ll say she already looked in that area. J Switch retains the “Pervert!” line, despite the fact that the item’s been changed to a necklace. On E Switch she says you can’t take a scale yet.
The owl statue by the bay has a really nice English translation. Japanese is literally “There’s a secret under the bridge.”
When refusing to give the fishhook to the fisherman, in Japanese he literally says “You have to be more kind!” but English refers to the fact that he often calls Link “buddy”.
For some reason, the fisherman’s text was changed between E GB and E GBC. E Switch keeps the GBC text.
Both follow the Japanese, but I kind of prefer E GB’s take on it.
When getting the necklace, J GB/C says “L-l-lucky!” and E GB/C + Switch follow suit. But J Switch changes the line to “Did someone drop this?”
When showing Schule Donavitch the mermaid scale, in English he says that he has to work on his drawing, except that it’s clearly a painting. The Japanese word 絵 (eh) doesn’t distinguish between drawing and painting. The translator(s) likely lacked visual context. Though to be fair, it is kind of hard to make out what he’s holding on GB/C.
After finishing the trading sequence, the mermaid comes back and explains that she modeled for an artist. On J GB/C + Switch she describes the artist as perverted.
When getting the magnifying lens, has a bit more text, reading roughly “Wow! This is a mysterious eyeglass, the foresight (lit. “see through”) lens!”
Schule’s reaction to the magnifying lens is slightly different in Japanese, roughly “What’re you looking at?! Could it be…my art?! That’s a magnifying lens, right?! Stop it! Don’t look at me!”
While other places on E Switch have changed “magnifying glass” to “magnifying lens,” one instance of “magnifying glass” remains in the Zora’s text as a holdover from E GB/C.
In Japanese the Zora’s text is slightly different, roughly “I want to live quietly, unlike those other guys.” Also Japanese has an extra line before giving Link the seashell, roughly “Oh well. Hold out your hand.” And E has an extra line at the very end, “A promise is a promise.”
Bonus: Seashell Palace text!
The Japanese has extra narration upon first entering, roughly “A voice echoes…in the deserted palace…” Also J says “sword with the power of light” vs. E’s “ultimate sword”.
When getting the second level sword, the E/J GB/C text has the voice saying that they’ve fulfilled their duty. On E/J Switch they just say to raise your sword so that you may get new power.
Also, the sword is now known as the “Koholint Sword” on Switch, as opposed to just a “new” sword. In Japanese it implies that your sword leveled up into this sword, while English is just “You got the Koholint Sword!”
Next we’ll take a look at some other side content before our journey to the Egg.