The L in “salmon,” the name of a fish, is not pronounced. It has to do with the way the word evolved through different languages. However, there is a surname, Salmon, in which the L is pronounced.
The word comes ultimately from the Latin salmon, but we got it by way of French, as we did with so many other food words. The French, as was their wont, had swallowed up the Latin L in their pronunciation, so by the time we English borrowed the word, it was saumon, no L in the spelling and so no L in the pronunciation.
The “L” in salmon is historically silent because the word was borrowed directly from the French word “sauman” (even though the L is present in the original Latin word “salmōn”) Salmonella was named after Dr. Daniel E. Salmon, who did pronounce the L in his name.
There is no L sound in Japanese, so they opt for the nearest sound they can manage, which is the Japanese R, a sound that English natives find it hard to master, and nothing like L at all in how it is articulated. The Japanese R approximates the English one but with a click, a tongue tap against the hard palate.
Japanese has one liquid phoneme /r/, realized usually as an apico-alveolar tap [ɾ] and sometimes as an alveolar lateral approximant [l].
In Latin, the word for fish is salmo, and the L is pronounced. Even though the English word spelling changed from samoun to salmon, the pronunciation stayed the same, making the L silent.
"Salmon" should be pronounced with an L sound.
L is also silent in could, should, would, as well as in calf and half, and in chalk, talk, walk, and for many people in calm, palm, and psalm.
One of the most common errors associated with production of /l/ is called gliding, where /l/ is substituted with a glide sound (/w/ or /j/). If your child is substituting a /w/ for an /l/, it's important to discuss relaxing the lips (or even having them in a slight smile) to avoid lip rounding.
The word salmon is spelled s-a-l-m-o-n, but is pronounced salmon. Small pronunciation errors like saying a silent letter are usually passed over by listeners. Saying a letter that should be silent doesn't usually interfere with communication, so it's really not a very big deal.
The loss of postvocalic /r/ in the British prestige standard in the late 18th and the early 19th centuries influenced the American port cities with close connections to Britain, which caused upper-class pronunciation to become non-rhotic in many eastern and southern port cities such as New York City, Boston, Alexandria ...
Lambdacism (from the Greek letter λ) is the difficulty in pronouncing l and similar sounds. Rhotacism is a difficulty producing r sounds in the respective language's standard pronunciation.
In Korean, the “l” and “r” sounds come from the same underlying consonant ㄹ. If you put your tongue in between making an “l” and making an “r,” you're almost there. The question is, when does it sound more like “r” or more like “l?”
When using English letters for Japanese, almost everyone uses the “R” character and drops the “L” from romaji, but the truth of the matter is that neither R nor L exist in Japanese. The sounds signified are usually written as “ra, ri, ru, re, ro,” but these aren't the same “r” as the ones we use in English.
Rather, the term polka dot current since the 1850's, has simply undergone the very common phenomenon of l-dropping : http://en.wikipedia.org/wiki/Phonological_history_of_English_consonants#L_vocalization_and_L_dropping while the term polka for the dance has retained it's /l/ due to reinforcement by foreign speakers ...
If an “L” is found towards the end of the word, before the letters “f,” “v”, “k” and “m,” but after the letter “a,” then it's usually silent (behalf, calve, walk, almond).