M (letter)
M is the thirteenth letter of the English alphabet. Its name is em, as in em dash (--).
Use in English
m is a hum, pronounced with the lips and voice, the first sound an infant produces: mmmm! Examples (the accents show stress and pronunciation: see English phonemes): múmmy mòther, míx, mâke, mòuse, moûsse eat = moôse animal.
It is only doubled in the middle of words, to keep the preceding vowel short: súmmer, slímmer, slímmed, slímming (cf. slím), dilémma, dúmmy, múmmy, lémming, accómmodate.
It begins consonant clusters: émber, ámbling, ámbry, amnêsty, émpty, Húmphrey, ámple, impréss.
And it likes to add a silent b at the end of some words: thúmb, lámb, cômb, númb, dúmb, tomb (*toôm). But not usually: slím, trím, whám, pómpom, thém, drêam, wårm, hím, húm, próblem, Ádam, hêlium, têdium, thêorem.
The prefixes in- and con- become im- and com- before p: impâtient, impàrtial, impráctical, complête, compônent, cómposíte, compôse.
Silent m: mnemónic (*nemónic) (cf. silent n in åutumn).
The double m following the double c in accommodátion (cf. commódity) is notorious.