What letters can parrotts or parakeets not say?

my parakeet can;t articulate the letter "L" just as many orientals can't articulate the letter 'r' E.G. flied lice for fried rice...my parakeet says tico me instead of tickle me "go seepy" when he wants to say "go sleepy" because he can't articulate the letter "L" Are parrots unable to say the letter "L" as well? Are there other letters parrots or parakeets can't articulate?