The Canterbury Tales, Chaucer's final unfinished work, is a creatively inflected compendium of contemporary genres set in the framework of a tale-telling game. The telling of an individual story relates in a complex way to the character of its narrator: the relation can be smooth ('The Knight's Tale') or tensioned ('The Prioress' Tale') and the matter is further complicated by moments in which Chaucer the narrator seems to take over from the narrator proper, or rather, seems to lend that narrator his "literary expertise" - referencing other texts - and his often ironic voice.
'The Merchant's Tale' can serve as an example of such complex telling. Part of the so-called 'marriage group', it ostensibly reflects, in its disillusioned perspective, the Merchant's own negative marital experience. At the same time, there are many 'generic' voices in the tale: romance, liturgy, Ovidian allusions, fabliau.
I suggest you look at and try to analyse the interplay of romance (here specifically the 'courtly love' variety) and fabliau elements in the tale and comment on the result. You might wish to ask what this combination says about the narrator's attitude to his subject-matter and the discourses he employs. Do you think the tale offers a critique of romance - or not?