'twas

'twas

 (twŭz, twŏz, twəz when unstressed)
Contraction of it was.

'twas

(twɒz; unstressed twəz)
contraction of
it was

'twas

(twʌz, twɒz; unstressed twəz)
contraction of it was.
References in classic literature ?
I knew 'twas a spring draf' goin' home, for there's no rig'mint hereabouts, more's the pity.
I stood forninst him, an' 'twas not me oi alone that cud tell Peg was dhrunk as a coot.
Faith,' thinks I, 'that's Honour an' Glory'; for 'twas Lift'nint Brazenose did that job.
If 'twas a woman I'd be willin', for they leave peace behind 'em when they go.
If 'twas our little Phelan, Jawn, I'd be breakin' me heart.
Miss Pollyanna told me long ago that she couldn't tell her, 'cause her aunt didn't like ter have her talk about her father; an' 'twas her father's game, an' she'd have ter talk about him if she did tell it.
But faith, if 'twas I, I should be as dry as a kex wi' travelling so far.
considering 'twas a wedding, and the folks well off), he found he'd never reach the fence and get over in time to save himself.
Presently they heard some one coming up the road whistling gaily, as though he owned the whole world and 'twas but made to whistle in.
The first had been delivered over the knuckles, and though 'twas a glancing stroke it well nigh broke Robin's fingers, so that he could not easily raise his staff again.
Each marnun' 'twas quinine an' gin for all hands on an empty stomach.
Twas nor'west-by- west, and the old Tryapsic down on the shoals.