Even in American English, there is a pronunciation difference between "calm" and "cam".
That makes me think of the "Mary", "marry", "merry" convergence, and wonder if there is any part of America where calm and cam sound the same?
I don’t think so.
“Calm” vs “cahm” is one thing (presence or absence of L, but same vowel), while “cam” has a different vowel.
Alphabetical spelling is an encoding of pronunciation.
In the original Latin, this encoding was probably efficient (I am not fluent in Latin).
As the Latin alphabet spread to other languages, including non-Romance languages (Germanic, etc.), the encoding became less consistent.
"Calm" vs "cam" is an example of a silent letter used in this encoding to differentiate between two different sounds, neither of which includes the "L" consonant.
Alphabetic spelling is an encoding of what we
think the pronunciation is, not what it
actually is (or ever was). In linguistics, these
conceptual speech sounds are called “phonemes”. But in actuality, many phonemes have multiple “allophones”, which are the actual speech sounds created, after application of the pronunciation rules of the language. (For example, English has two different “k” sounds (allophones), but because they occur in mutually exclusive situations, we mentally collapse them down to a single “k” phoneme.)
Alphabetic spelling is based on phonemes
at most, so they are not complete guides to pronunciation even in languages often considered to have highly regular spelling, like German.
Anywho, in your original comment about calm, what do you mean by “cam”, then: the things camshafts have multiple of, or the word “calm” with a silent L?
Because the issue is that there are THREE pronunciations to deal with:
Calm with L pronounced
Calm with silent L
Cam