Translation of "The Merchant's Prologue" courtesy Gerard NeCastro, University of Maine at Machias.
The Merchant's Prologue
The Prologue of the Merchant's Tale
"About weeping and wailing1, care and sorrow, I know plenty," said the Merchant, "both day and night, and so do others who are wedded, I believe. Well I know it is so with me. I have a wife, the worst one possible; for even if the Fiend were coupled to her, I dare well swear she would outmatch him. Why should I rehearse to you all the points of her great malice? She is an evil creature in every way. There is a long and large difference between Griselda's2 meekness and the surpassing cruelty of my wife. 
"If I were unbound, never again would I come into the snare3, by my head! We wedded men live in worry and sorrow. Try it, those who wish to, and they shall find, by Saint Thomas of India4, that I tell the truth, at least for the greater part--I speak not of all. May God save us, if it should be so! 
"Ah, good sir Host! I have been wedded these two months, and not more, by God! And yet I believe that he who has been wifeless all his life could in no way, even if men would tear him to the heart, tell so much sorrow as I now could tell here of my wife's cursedness!" 
Our Host said, "Now, Merchant, may God save your soul, since you know so much about that business, I pray you heartily, tell us a part of it gladly." 
He replied, "Only from my own pain will I, for my sorry heart I can tell no more." 
1 weeping and wailing The epilogue of the Clerk's Tale, the tale preceding this one, has just ended with a note that to get the upper hand in marriage, women should work and let their husbands worry, weep, and wail over the trouble their wives cause them. The tone is ironic, since the tale itself presents the point of view that women should be subservient to their husbands.
Source, "The Merchant's Prologue" translation: NeCastro, Gerard. eChaucer. U of Maine at Machias, 2011. Web. 17 Oct. 2011.
2 Griselda The clerk has told the tale of patient Griselda, a woman who endured the many hardships and cruelties set forth for her by her own husband, who was testing her loyalty.
3 the snare i.e., Of marriage.
4 St. Thomas of India St. Thomas the Apostle, who, according to legend, traveled to India to convert thousands to Christianity.