bitextual
Let me preface this by saying that my grammar and storytelling abilities are nothing great, even sticking to just one variant of English.
As someone born and raised in India, my early education mostly adhered to British English spellings and vocabulary. All of my textbooks used spellings like colour, behaviour, analyse, etc. Words like lorry, chemist, torch, and flat were part of my everyday vocabulary. Growing up, I didn't think twice about the differences between British and American variants.
However, things got a bit complicated when I started working. Many companies I've worked for have had their main operations and target audiences in North America. The biggest adjustment has been around spellings with "z" instead of "s." Words ending in "-ise" or "-isation" look far more natural to my eye than "-ize" and "-ization" counterparts. Then, I had to deal with the grammar conventions, slang terms, and idioms. Pushing myself to use the American variants in my writing has taken conscious effort.
Even now, years later, I often find myself stuck between the two variants. I naturally tend toward British spellings when writing on paper or filling out official forms. I switch to the American style for web content to ensure clarity for all readers.
The transition has also caused some funny moments in my personal life. My wife, who is Chinese, tends to use American terms like "elevator." Meanwhile, I still slip and say "lift" occasionally. Overall, being straddled between the two main types of English has been a unique challenge for someone from neither culture.
image: remix of a flork.