Lambdacism
Lambdacism is the inability to pronounce or difficulty in pronouncing l sounds. In general, /r/ is usually substituted for /l/, as in Japanese. The native Igbo-speaking communities in Southern Nigeria are also known to have the interchange common while pronouncing Igbo and English words.
A common form of lambdacism is lallation. The substitution of /l/ for /ɹ/ in pronunciation, it is a common feature of Japanese and Korean pronunciation of English. Substitution of /l/ for /n/ at the beginning of a word or syllable is also a feature in certain East Asian languages, such as the Northern dialect of Vietnamese as well as Cantonese and Thai.
