In Margaret Atwood's poem "You Begin," she explores the concepts of language and metaphor through the lens of teaching/learning them. The speaker of the poem seems to be talking to a young child as the child draws pictures, and it is through this child-eye-view of language that the reader is challenged to think about how words, metaphors, symbols, and reality intertwine.
Atwood's choice to frame this discussion of language learning (and teaching) through the child drawing pictures is especially significant. Before humans had language based on a written alphabet and words, we used pictures and visual representations to express our ideas. Atwood shows the way a child learning language still follows this progression to some extent, but how this overlapping of word-based language and picture-based understanding can allow for metaphor. In the line, "This is your mouth, this is an O / or a moon, whichever / you like," we see the drawn circle has the possibility of being a letter, or a representation of two different physical objects, which then pulls them into comparison with each other.
When the speaker says, "This is the world, which is fuller / and more difficult to learn than I have said," they sandwich that thought between the limited number of crayons in the child's box and their approval that the child has found out how to smudge the colors together. In learning to understand the world through what we are given (a number of colors, a certain language, a teacher's view of the world), one inevitable step is learning how to go beyond the given and create something new. Visually, this would be smudging the colors together. Linguistically, it might be combining words into new combinations as metaphors, poems, or stories. In education, it might be going beyond what the teacher says/thinks in order to form one's own views of the world.
The poem ends with the lines: "It begins, it has an end, / this is what you will / come back to, this is your hand." Here, the speaker zooms out onto life as a whole. In saying to the child that they will begin and end (be born, live, and die), and that it always comes back to "this is your hand," the speaker is saying that the great human effort is making sense of oneself and one's life through whatever means we can—language and metaphor, visual representation, the physical body.