When thou canst get the ring upon my finger which never shall come off, and show me a child begotten of thy body that I am father to, then call me husband: but in such a 'then' I write a 'never.'
When you can get the ring on my finger which will never come off, and show me a child born from your body that I'm the father of, then call me your husband: but in that "then," I write "never."
Bertram, Count of Roussillon · Act 3, Scene 2
Bertram sets impossible conditions for consummating his marriage, believing them literally impossible to achieve. The line is central because it establishes the conditions that Helena will later fulfill through the bed trick. Bertram's confident 'never' becomes the play's ironic turning point: what seems impossible becomes inevitable through female agency and cunning.