THe first letter of the alphabet serves many linguistic purposes and numerous grammatical functions. One that has intrigued this writer is the way in which a humble lower case "a" prefix can semantically transform different types of words. This can be in terms of a manner (loud, aloud), a condition (live, alive), a state (lone, alone), or action (rising, arising). Relevant applications can be with nouns, verbs (particularly with present participles), adverbs or prepositions.
Bernard, Thomas L.
"The Power of "a" Prefix,"
Word Ways: Vol. 36
, Article 19.
Available at: http://digitalcommons.butler.edu/wordways/vol36/iss4/19