(literary or archaic, also occasionally colloquial) itis.’Tis the season to be jolly. — Popular Christmas song ("Deck the Halls").’Tis good ta’ ’ave ya back boy! (to have you)’Tis a shame!’Tis but a scratch!
1597, William Shakespeare, Romeo and Juliet, Mercutio wounded: "No, 'tis not so deep as a well, nor so wide as a church-door; but 'tis enough, 'twill serve: ask for me to-morrow, and you shall find me a grave man."
1844, Charles Dickens, The Chimes, It looks well in a picter, I've heerd say; but there an't weather in picters, and maybe 'tis fitter for that, than for a place to live in.