posted by John .
How do you pronounce the l sound? Do you know how to say the l sound? Put the front part of your tongue on the gum in your mouth, and let the air pass on both sides of your tongue, saying l.
What about the r sound? Can you speak the r sound? What is the difference between the l sound and the r sound?
When you say the r sound you should bend the front part of your tongue. However your tongue should not touch the roof of your mouth. And make the air pass on both sides of your tongue, saying r.
Are the expressions above grammatical? If you find unnatural expressions, would you correct them?
Can we use 'alveolar ridge' instead of 'gum'?
The expressions are grammatical. "Alveolar ridge" is seldom used except by speech teachers or specialists.
The word "gum" in this context refers to the tissue that holds the teeth in place. I think you're referring to the roof of the mouth (the more common expression for alveolar ridge).