Compare Mr. Van Daan’s words here with his comment to Anne in lines 1271–1273 of Act One. What is the impact of Van Daan again using the word discussion rather than quarrel? What is ironic about Mr. Van Daan’s use of the word selfish?

In these lines, we see Mrs. van Daan arguing with Mr. van Daan. We learn that Mr. van Daan is finding it really difficult to have peaceful relationships with other people. He does not understand the children's needs for privacy, nor does he understand why everyone needs space. He is annoyed at Anne for lying on the floor writing, and Mrs. van Daan loses her patience due to her husband's bad mood.

Anne is surprised at the fact that adults quarrel, as she believed that only children did so. However, Mr. van Daan tells her that they are not quarrelling, but rather having a discussion. He uses this word because it conveys a less negative idea, as well as makes him appear more mature. It is also ironic that Mr. van Daan refers to Anne as selfish for her habits, when he is the most selfish character in the story, and the one who cares the least about others.

type of error:

the error in the sentence is a "dangling modifier". a dangling modifier is a phrase, word or clause that "dangles" because there is not target to modify. in this case, "after mopping the floor" is the dangling modifier since it has no word to modify. the noun "house" cannot mop the floor; therefore there is a mistake in the writing of the sentence.