Moratín's El Si de las Niñas is the crowning masterpiece of 18th century Spanish drama. Its original success and continuing interest derive from the author's ingenious exploitation of the comic potential and serious social implications of the contemporary custom of arranged marriages. With great psychological insight, Moratín, explores the dilemma of a 59 year old man about to marry a 16 -year old girl he has only just met, bringing out the mixture of comedy and pathos in a delicate situation. When the suitor's rival turns out to be his nephew, the emotion tension mounts until, amid a complex web of ironies, reason finally prevails. The introduction sets both social and literary aspects of the this serious comic drama in the context of late 18th century Spain, taking into account the findings of recent research on the author and his times. The text is based on the author's final version of the play and the accompanying notes elucidate difficult words and phrases as well as pointing out significant literary and historical features.