To prononce English L you need to hit the back of your upper teeth with your tongue, but to prononce らりるれろ our tongue softly hit our upper jaw. Of course, the sound is quite different from English R sound.

Japanese R is not like English R nor L. > how are they different from the English pronunciation? Here are resources. https://www.youtube.com/watch?v=PS0svLNkrb8 https://www.youtube.com/watch?v=6-ERE23YP88

Here is a short answer. I'll let experts give a long answer. The Japanese /r/ phoneme sounds somewhat "l"-like and "r"-like to English speakers. Like the English /l/, the tongue tip touches the alveolar ridge for Japanese /r/. However, it is a quick tap or flap, much much shorter than the English /l/. It is similar to the American English flapped /t/[ɾ] as in "better" and "letter" and the Spanish flapped /r/[ɾ] as in "cara." From wikipedia: https://en.wikipedia.org/wiki/Help:IPA/Japanese ɾ ろく, そら roku, sora American better (flapped t)