Wikipedia has a detailed explanation. /r/ is an apical postalveolar flap undefined for laterality. That is, it is specified as neither a central nor a lateral flap, but may vary between the two. It is similar to the Korean r. To an English speaker's ears, its pronunciation varies between a flapped d ([ɾ], as in American English buddy) and a flapped l [ɺ], sounding most like d before /i/ and /j/, most like l before /o/, and /a/, and most like a retracted flap [ɾ̠] before /e/. It is occasionally realized as a trill [r], especially when conveying a vulgar nuance in speech. The phenomenon is called rolled tongue (巻き舌 makijita) in Japanese, and is usually transcribed by repeating katakana ru, e.g. ガルルルル for a dog's growl. It is sometimes transcribed with an l–ɾ ligature, lɾ. Japanese phonology - Wikipedia, the free encyclopedia
Wikipedia has a detailed explanation. /r/ is an apical postalveolar flap undefined for laterality. That is, it is specified as neither a central nor a lateral flap, but may vary between the two. It is similar to the Korean r. To an English speaker's ears, its pronunciation varies between a flapped d ([ɾ], as in American English buddy) and a flapped l [ɺ], sounding most like d before /i/ and /j/, most like l before /o/, and /a/, and most like a retracted flap [ɾ̠] before /e/. It is occasionally realized as a trill [r], especially when conveying a vulgar nuance in speech. The phenomenon is called rolled tongue (巻き舌 makijita) in Japanese, and is usually transcribed by repeating katakana ru, e.g. ガルルルル for a dog's growl. It is sometimes transcribed with an l–ɾ ligature, lɾ. Japanese phonology - Wikipedia, the free encyclopedia
So more or less like most languages that have a trill on some of the words, this is exactly the same?
If for example, I am unable to perfect this trill(tremble) would I still be understandable?
The point being that it is similar to English "d" when pronouncing things like "buddy" where the tongue is not right against the teeth. Ignore the part about trilling.
The point being that it is similar to English "d" when pronouncing things like "buddy" where the tongue is not right against the teeth. Ignore the part about trilling.
This is the reason you can ignore it. Unlike in Spanish, trilled and untrilled /r/ are not separate phonemes in Japanese, i.e., they are recognized as the same word in either pronunciation.