I remember in first grade, there was an American boy in my class. One day when we were writing stories, he spelled “mum” as “mom” and it was marked as a spelling error.

Do you think teachers should mark both American & British spelling as correct, or should only one be correct?

For example, should the following words be marked as correct in the US?

Favourite, mum, colour, flavour

Or should only the following be marked as correct?

Favorite, mom, color, flavor