Americans please can I have your opinions

nah, say something to that teacher.

been is "bin"
seen is "suh-een"

nobody is saying where have you 'bean', teach needs to stop being ridiculous because been doesn't go with seen/keen

been
is are was were be, been.

sight yes but not categorized like how they did it.

I taught a lot of kids where English was not the first language. Obviously English is the first language in your case but the same rules should apply. It should be counted as right because it is right for him. You can’t count off for Accents! The teacher should take this into account.

Teacher is ridiculous,

in American English it is typically pronounced as “bin” but the typical British English pronunciation is “bean” which like Haley said, is an accent / regional dialect difference, not an incorrect answer.

The teacher is correct BUT if your son has an English accent it is completely unfair to mark him wrong, he can't help how he talks. You should definitely address it

It depends where in the US you are that some words can be a slightly differently pronounced. But been sounds like bin and half sounds more like haf than hof. If the goal is to teach him to speak in the correct accent the teacher is right to correct him however he should understand that his pronunciation is not incorrect, just not the local dialect being taught. Which is how he learned to switch accents on cue

Teacher here and no way should his accent be held against him— another example would be a student with speech delays/articulation errors- these would be taken into consideration as the student’s speech NOT counted as incorrect.

Side note though, I pronounce been as “ben”/ short e, not i. 😆 🤷‍♀️

Accents in the UK are incredibly varied. I'm from the west country, live in the midlands, and have a northern husband. There are some words that my husband, daughter, and I all pronounce differently! Doesn't make any of them 'wrong'. The teacher absolutely should take that into account.