The /l/ sound is one of the sounds that is more frequently misarticulated. The /l/ is often substituted for /y, w, r/. For non-native English speakers, the /l/ may not be present in their native language making acquisition of the /l/ sound a bigger challenge.
The letter /l/ is made by placing your tongue up behind your top front teeth. Feel the bumpy part with your tongue. Hold your tongue up and turn on your voice. Your breath should pass along both sides of your tongue and through your open lips.