a- as a particle

a- as a particle

Many words in Shakespearean texts begin with a- used as a grammatical particle (an element which affects the meaning of other words but without any dictionary meaning itself). The commonest use is before a verb ending in -ing (coming, going), to which it is usually shown linked with a hyphen. Historically a form of on, it came to be used as a particle emphasizing various aspects of the verb’s durative meaning, such as the repeated nature of an action or the length of time it takes. On this basis, to be ‘a-feasting’ is, as it were, ‘to be engaged in the time-consuming activity of feasting’ (MW II.iii.80). The meaning is often reinforced by accompanying temporal adverbs, as in the Scrivener’s complaint about the time it took him to write out Lord Hastings’ indictment (R3 III.vi.7): Eleven hours I have spent to write it over...
The precedent was full as long a-doing
  For activities which are not by nature durative, such as kill, the use of a- can be particularly dramatic, as in Othello’s wish to extend the time-frame for Cassio’s death (Oth IV.i.177): ‘I would have him nine years a-killing!’ And the form can be used with various ironic overtones. Its repetitive or habitual implication can add a sense of routine or ordinariness to an activity, thereby conveying a demeaning effect when used with reference to activities which are very serious in nature: a-dying (R2 II.i.90), a-praying (Ham III.iii.73), a-hanging (KL V.iii.272).
Often the role of the particle seems little more than to add an extra syllable to make up the metre of a line. Because sleeping, for example, already implies duration, little is added semantically by the addition of a-, so that its function in Apemantus’s Grace (Tim I.ii.66) is purely metrical: Or a harlot for her weeping, Or a dog that seems a-sleeping.

Other examples of a- particle usage include:

a-bat-fowling Tem II.i.188 a-hunting TNK III.vi.108
a-begging TNK III.vi.238 a-making Ham I.iii.119
a-billing Ven 366 a-maying TNK III.i.1
a-birding MW III.iii.218 a-mending TC I.iii.159
a-bleeding MV II.v.24 a-repairing LLL III.i.188
a-breeding LLL I.i.97 a-ripening H8 III.ii.357
a-brewing MV II.v.17 a-rolling H8 V.iii.104
a-capering MV I.ii.58 a-shaking Luc 452
a-coming LLL V.ii.581 a-shouting JC I.ii.221
a-doting Sonn 20.10 a-sleeping Tim I.ii.66
a-ducking AC III.vii.64 a-swearing Ham III.iii.91
a-going H8 I.iii.50 a-turning PP 7.16
a-growing R3 II.iv.19 a-weeping 2H4 II.iv.272
a-hooting LLL IV.ii.60 a-wooing Oth III.iii.71

A second use of a- as a particle occurs in front of adjectives, where it commonly adds a degree of extra intensity or emphasis: to be ‘a-hungry’ typically implies a somewhat greater strength of the condition than to be simply ‘hungry’: a-cold (KL III.iv.80, and often so used by Poor Tom), a-hungry (MW I.i.251) or an-hungry (Cor I.i.203). Here too the particle can be a useful way of adding an extra metrical beat to a line, as in R3 IV.iv.86 [Queen Margaret to Queen Elizabeth]: ‘One heaved a-high to be hurled down below’.   These uses of a- should be distinguished from a- as a prefix (a meaningful element attached to the front of a word). Here a- represents the unstressed form of a preposition in front of a noun, usually joined to the rest the word by a hyphen (a-bed, Cym III.iii.33), sometimes printed solid with it (abed), and occasionally left spaced (as in the First Folio printing, a bed). It is most commonly found as a variant of on (and replaced by o’ in some text editions), as in these examples from Pericles: a-land (Per II.i.28), a-th'land (Per II.i.33), a-shipboard (Per III.i.1).