So how come Vernon is fluent in speaking english but not HueningKai?

Very simple: HueningKai was born in hawaii but lived in China before Korea so he did speak English but his environment spoke Chinese then Korean when he moved.

(poor attempt btw)

Quote from uknowwhat

But Vernon moved to SK when he was 5 or younger but he still speaks like a native one.

Maybe Hueningkai's family spoke mostly korean at home, not english.

He lived with only his mother in Korea for a majority of his childhood as his parents got divorced when he was a child (at least that's what other fans have told me). So i would assume that the primary english speaker (his dad) wasn't always in his day to day life.

Because they're not the same people and therefore have different experiences, lives and learning abilities and memory. Vernon's mom is American so she probably spoke English to her children and therefore they learned it much easier.

Huening Kai's mother is Korean and father was born in Brazil, moved to America when he was four and then moved to Hong Kong when he was a teenager. He could also not treat English as his native language and didn't speak it much to his children and if Huening Kai didn't have an affinity for it in school it makes sense that he wouldn't speak it as well as Vernon speaks it. Vernon also had Joshua in his group so when he was away from home to train, the two of them could speak in English and he could continue honing his skills with him as well.

Quote from Pinky_Peachy

Because they're not the same people and therefore have different experiences, lives and learning abilities and memory. Vernon's mom is American so she probably spoke English to her children and therefore they learned it much easier.

Huening Kai's mother is Korean and father was born in Brazil, moved to America when he was four and then moved to Hong Kong when he was a teenager. He could also not treat English as his native language and didn't speak it much to his children and if Huening Kai didn't have an affinity for it in school it makes sense that he wouldn't speak it as well as Vernon speaks it. Vernon also had Joshua in his group so when he was away from home to train, the two of them could speak in English and he could continue honing his skills with him as well.

Yes to most of what you said but apart from being born in Brazil, Kai's father and paternal family are American and full English speaker but yes being in China and Korea brought him to two non English environment and three languages at the same time. When you hear him speak he has great pronunciation but stumbles a lot on words, which isn't surprising when you've been surrounded by various languages

Quote from Anpanromane

Yes to most of what you said but apart from being born in Brazil, Kai's father and paternal family are American and full English speaker but yes being in China and Korea brought him to two non English environment and three languages at the same time. When you hear him speak he has great pronunciation but stumbles a lot on words, which isn't surprising when you've been surrounded by various languages

That makes a lot of sense!

He only living in Hawaii basically 1 month after he was born. Then move to China.