A friend learned English from an Italian teacher, she had an Italian accent when speaking English. She doesn’t speak a single word of Italian or ever studied Italian. Pronunciation has nothing magical to it, and accents are very flexible. I can speak in almost any accent I want (thanks to linguistic training), but I tend to naturally and unconsciously gravitate towards the accent of the person I’m talking with. It makes others uncomfortable sometimes (those who have learned many languages and thus notice it), but most people don’t notice and think they actually like me because I talk like them. On my own, the most natural would be Austin, Texas English pronunciation. But it’s because of my heavy consumption of YouTube and Twitch content from that area during my teenage years, I’ve never been in the US. In Spanish I have like three or four different accents depending on the topic and context, code-switching is very common.

It’s the kind of thing that goes unnoticed when you don’t learn any new language or only speak a single second language. If you never interact with anyone who speak differently than you, then you don’t notice that the way you speak is not universal and you probably have a “heavy accent” in front of others who speak your same language.