Why can some people roll their r's while others can't?

I wonder how common the inability to do it is in people whose native language is one that contains the trilled r. It seems that people who are raised speaking those languages develop the ability to do it at a young age so it's less likely they'll have a problem with it.

But then again I pronounced r's like w's until I was practically 10. 🤔

They probably don’t speak Spanish fluently or didn’t learn it as a child and simultaneously with their primary language.

I grew up speaking Spanish, so they just roll off my tongue 😁

the best way to practice is to do it while gargling with water

because many don't give it a shot. they just give up

Practice makes perfect!

I prefer to roll my K's

I cant

Genes

I grew up with French-speaking grandparents, so the “r” is very different, almost like gargling it. I just [b]can’t[/b] roll my rs properly. My sister, who has a better ear for languages can speak both, but even she fudges the Spanish r a little bit, because she also spoke French first.

Because you didn't learn to do it when you were young and your language skill were developing. You could learn to do it but it becomes difficult to train your tongue in adulthood.