R is a bit of slippery Chinese pronunciation. At the beginning of words it’s very similar to the English “r” but with a slight buzz but certainly not as strong as a rolled Spanish “r”.
Instead it’s somewhere between the English “r” and “l” sound so takes a little bit of practice to locate the correct sound.
To find the Chinese “r” say the English word measure. The middle –s- of measure has a very similar buzz to the Mandarin “r” sounds.
Say “measure” and hold the vibration at the centre of the word. Can you feel the buzz? That is the Chinese “r” sound. Alternatively use the word “Asia” and feel the buzz on the “s”.
You can hear recordings on the Chinese R as well as get more detailed instructions here in our Sensible Pinyin course.
Using the English r- sound is often acceptable and you will be understood. However, if you want your pronunciation to be authentic make sure you find the sweet spot between “r” and “l” where the Chinese “r” actually resides.
The real test of whether you’ve got the initial –r correct is the word 日 rì, which sounds totally off when said with the English r- sound. Practice this with a native speaker as the ultimate test of r- mastery!