The owl has a bit of a “stately old man” flair in Japanese, befitting a guide. This is in contrast to Ulrira, who’s got more of a casual old guy vibe going, and the other villagers who all speak colloquially with varying accents.
In Japanese Sale references the starving artist trope and says he feels his brother would be better off if he had good things to eat. In English he simply notes that strange hobbies must run in the family.
In the Switch version, after obtaining the sword, the kid by the Trendy Game gets new lines to encourage the player to win the Yoshi doll and bring it to his mom, since it’s required to open up the third dungeon. (Incidentally, rupees drop much more frequently on Switch.)
The text upon winning the Yoshi doll has been updated on the Switch version to reflect how many games Yoshi has been in now, but only in English. The Japanese text remains the same.
CiaoCiao continues to repeat the same line after getting the bow in the GB/C version, but loses the ability to speak in the Switch version. (The same is true in Japanese.)
When giving the canned food to Sale, the line has been tweaked a bit between the GB/C and Switch versions. Perhaps because the Switch version has nametags now, clearly showing that Sale is still speaking. (The line is unchanged in Japanese.)
During the trading quest, the Japanese has fun cheeky options for saying yes or no which are different every time (like “Dun wanna!” “Nuh-uh!” kinda stuff). English tends to stick to pretty basic responses, maybe adding an exclamation mark, but that’s it.
The sign in front of the forest has changed a bit between GB/C and Switch in both languages, probably to alert new players of the danger ahead. The Switch Japanese literally reads: “Dangerous! Currently a huge outbreak of Moblins!”
The owl’s line in Japanese at the start of the forest is slightly different, roughly: “You won’t find Koholint Island on any map. It runs on a different kind of logic than your world, boy.” Though the English’s “Much of mystery” has a very nice ring to it.
In Japanese Tarin is named “Mischievous Tanuki” and says “ponpokopokorin.” “Ponpoko” is the sound tanuki make when they drum on their bellies in Japanese folklore. (Thus the Ghibli film Pom Poko.) Also his line kinda rhymes in Japanese.
In Japanese, the sign in front of the cave in the forest says something like “Heavy people shouldn’t walk on them (cracks)!” Which the GB/C version translates literally. But this was revised in the Switch English version to give more helpful advice. (The line remains the same in Japanese.)
In English the witch has fun witch-y lines that rhyme. (Selling powder for rupees is new as of the Switch version, I believe.)
In Japanese she just sings “toro-ri, torori” but otherwise talks like a regular old woman. (To be fair, there isn’t really any kind of distinct “witch-speech” (that I can think of!) in Japanese.)
Tarin’s English lines after transforming back into himself are nicely written, perfectly fitting the tone he has in Japanese.
Next is the first dungeon!