Date Originally Created: March 6th, 2024
My native language is English, but I am able to speak Russian, Spanish, Mandarin, and German (though with German, I'm a bit rusty as I haven't used it in a while). One thing I had trouble with for the longest time was the Rs in Russian and Spanish when I was learning both of them, but that's because even though the Rs sound similar, they're different.
This is my second language, so I'm putting it first. There are technically four types of Rs in Russian, the post-alveolar tap, the post-alveolar trilled R (not usually used in informal settings, and even formal settings), the tapped palatized R (I can't say for certain if this is common or not, but I have heard it used a lot), and the trilled palatized R (the more common palatized R, used in words such as "Теперь", where the ь is palatizing it, refer to the diagram at the top of this page). Note that palatized means done behind the teeth (despite what's shown in the diagram). The palatized ones are similar to the Spanish Rs, but that'll be covered in the next section. The Trilled Rs are typically softer, and usually only fluttered twice, as opposed to the Spanish version where it's harder and fluttered four times.
The Spanish R is done on or in front of the alveolar ridge, both tapped and trilled. The trilled R in Spanish is also more rapid (fluttered four times) and sounds harder than the Russian trilled R.
If you wanna (try to) learn to trill your Rs in either language, THIS ARTICLE should probably help, just note that to apply this to Russian, just apply it to the post-alveolar ridge instead of directly on or in front of the alveolar ridge (refer to diagram in either article).