英文词源
- a- (1)
- in native (derived from Old English) words, it most commonly represents Old English an "on" (see a (2)), as in alive, asleep, abroad, afoot, etc., forming adjectives and adverbs from nouns; but it also can be Middle English of, as in anew, abreast (1590s); or a reduced form of Old English past participle prefix ge-, as in aware; or the Old English intensive a-, as in arise, awake, ashame, marking a verb as momentary, a single event. In words from Romanic languages, often it represents Latin ad- "to, at."
[I]t naturally happened that all these a- prefixes were at length confusedly lumped together in idea, and the resultant a- looked upon as vaguely intensive, rhetorical, euphonic, or even archaic, and wholly otiose. [OED]
- a- (2)
- prefix meaning "not," from Latin a-, short for ab "away from" (as in avert); see ab-.
- a- (3)
- prefix meaning "not," from Greek a-, an- "not," from PIE root *ne "not" (see un-).
中文词源
a-（单词前缀）：构成众多英语单词的常见前缀
1.衍生于古英语an(现代英语on），连词of, 古英语前缀ge-(同前缀con-），或表示加强语气，附着于名词，形容词，动词之前构成形容词，副词，动词，词义基本保持不变。因这些附着词最后都缩写成a-, 且所表示的功能相似，语法趋同，由相互混淆到最后相互融合。见alive, asleep, afresh,arise, aware.
2.来自ab-, 偏离，非。见avert, avocation.
3.来自an-, 非，否，应用于辅音词根，在古英语中并未明确区分。见atypical, apolitical.
4.来自ad-, 表示去，往，通常来自于古法语。见aver, avow.
5.来自ex-, 表示出，向外，或强调义。见affray, amend.