What are some examples of situational irony and verbal irony in Trifles?
Glaspell's play Trifles (1916) takes as one of its subjects the dismissive treatment of women by men--in this case, the sheriff's wife, Mrs. Peterson, and the farmer's wife, Mrs. Hale--who are present simply to gather some clothes and personal items for Mrs. Wright, who appears to have killed her husband. The men carrying out the investigation assume, based on their bias toward women, that the two women cannot add anything significant to the investigation.
The play is framed by the situational irony created when the men go upstairs to look for evidence relating to the murder and leave the women in the kitchen. The County Attorney and Sheriff's goal is to find evidence of a motive, but they dismiss the kitchen--the woman's domain--immediately:
[the County Attorney to the Sheriff] "You're convinced that there was nothing important here--nothing that would point to any motive?" [the Sheriff responds] "Nothing here but kitchen things."
Ironically, the men have completely ignored the most important room in the Wright's house from a woman's point of view--the accused Mrs. Wright probably spent more time here than anywhere in the house. As we learn in the next scene in the kitchen, the two women discover the irregular sewing on a quilt, the broken bird cage in a kitchen cabinet, and, more important, a dead canary with its neck broken wrapped in silk in a sewing box.
As the women examine the quilt, for example, they discuss whether Mrs. Wright was "goin' to quilt it or just knot it?" The Sheriff and County Attorney's response to their question is laughter, the implication being that the irregular sewing and knot issue cannot be relevant to solving the case. The great irony here is that, while the men are upstairs or outside looking for clues, the two women are in the "heart" of the house where all the clues to Mrs. Wright's motive reside. The word knot later becomes a masterful example of verbal irony.
Later, when the Sheriff and County Attorney are examining the items the two women intend to take for Mrs. Wright, which includes the dead canary, the County Attorney says,
"Oh, I guess they're not very dangerous things the ladies have picked out. . . . No, Mrs. Peters doesn't need supervising. For that matter a sheriff's wife is married to the law."
There are several ironies here: 1) The County Attorney assumes the women have picked out only appropriate items, but we know they have essentially erased (by fixing the quilt) or hidden anything that would incriminate Mrs. Wright; 2) Mrs. Peters, the Sheriff's wife, does indeed need supervising, but the County Attorney assumes she is acting in accord with her husband because he cannot envision her exercising any independent judgment; and 3) at the beginning of the play, one could argue that Mrs. Peters is a good representative of her husband--that she is indeed "married to the law"--but in this scene, she is willfully withholding evidence because she identifies with Mrs. Wright rather than the law.
A wonderful example of verbal irony occurs in the last lines when the County Attorney "facetiously" comments that, even though they have failed to find a motive, they have determined (because the women have focused on it) that Mrs. Wright's quilt was knotted--"We call it--knot it, Mr. Henderson." This is rich irony in that Mr. Wright was strangled in his bed by a knotted rope. If the men were paying attention, they might have connected the construction of the quilt with the method of Mr. Wright's death, but because they dismiss the women's comments as unimportant, a chance to connect Mrs. Wright to the murder slips away.
Here is a video further explaining the different types of irony: