Speaker (The Widow)
The speaker of the poem is a recently widowed woman. She pays close attention to details in nature. She spends the majority of the poem contrasting the beauty of springtime's bloom with her pain from the loss of her husband. She chooses to highlight the way in which the view of their backyard formerly brought her great joy, but now fails to do so because of the absence in her life. While the speaker is clearly a character—and not a stand-in for Williams—she is like the poet in that she has an eye for poetic comparisons that never lapse into overtly abstract language. She is clearly heartbroken with grief.
Deceased Husband
The speaker's husband is never described directly. However, given the depth of the widow's feelings, it can be intuited that he was well-loved. This fact can also be presumed from the way in which she speaks about their yard and the accumulation of time that they have spent there. Her focus on the grass and trees in their backyard demonstrates the level of care that went into the life they built together.
Son
The speaker's son is not described in much detail. He appears at the end of the poem and mentions a tree with white flowers to his mother. This small gesture reveals a degree of compassion in their relationship.