My impression is that the concept of a silent "n" is quite common in many different languages/linguistic families . What is the reason that the "silent n" is so common in language as opposed to other sounds? Also, can someone bring examples of languages other than those related to English which have this phenomenon (particularly Semitic languages)?
The phenomenon is called Consonant Clusters. They exist in quite a few languages, including the ancient ones. With the course of language's evolution, contraction may occur, effectively changing the phonetic value of these clusters.
Reduction of /mb/ and /mn/. Where the final cluster /mn/ occurred, this was reduced to /m/, as in column, autumn, damn, solemn. — Wikipedia
The same Wikipedia article also refers many other consonant clusters of English and rules of their (modern) pronunciation.
There are also academic works on the subject:
- Heinz J. Giegerich (1992) researches consonant clusters in terms of generative phonology;
- Peter Roach (2002) — a more traditional structural analysis of possible phoneme combinations;
Note that the phonological value of consonant clusters may vary even within the same language, across its various dialects.
As consonant clusters exist in many languages, they may appear contracted in different ways.
Greek language has variety of consonant clusters and quite a complicated set of rules of their contraction. Most notable one is maybe ντ = /d/:
- Ντέμης /Demis/, an equivalent of men's name Dennis;
- Αντωνης /Adonis/, an equivalent of men's name Anthony;
- αντεννα /adena/ "antenna";
You may find a comprehensive list of Greek consonant clusters here.
Thai also has consonant clusters and they are often reduced in informal speech. Most notably,
[kʰl] are retracted to
[kʰráp], an affirmative/polite particle, is often pronounced
Summary. The consonant clusters exist in many languages. They may appear contracted (reduced) in various manners within the language or its dialects. Each language has its own laws of phonetic harmony, and such contraction occurs according to these laws.
There's no common rule, except the statement that the phenomenon exists.
Final consonant cluster reduction happened in English, and most of the '-mn-' examples mentioned in the above comments did not survive into modern Spanish or French either (unless they were re-borrowed from Latin), although they lost /m/ instead of /n/. It's possible that process had already started when the words were entering English.
Specifically for Semitic languages it seems unlikely there would be very similar processes, due to importance of triconsonantal roots.
See also: Korean dialects