One metaphor that seems to drive the entire poem is the use of various school grading systems as a tool to evaluate the speakers completion of household chores. This type of metaphor that drives the entire poem is called a controlling metaphor, since it controls the entire poem. "Marks," the title of the poem, gives way to this metaphor. Usually this word is defined as a mark as a spot or line on a piece of paper. This literal meaning of this term doesn't allow for much insight into this metaphor. However, if one looks at the connotative meaning of the word mark, there is much to gain. Often, many of us associate the word mark with grades received in school. This is precisely what the title of this poem is refering to. This idea of marks as grades is illustrated with the speakers family members. Each family member has their own grading system to evaluate the speaker. The husband uses a letter grading system, the son a ranking system, and the daughter simply grades her mother on a pass/fail system. As you can see, there is extensive textual evidence to support this metaphor.