What are some modernist characteristics of Langston Hughes's poem "Mother to Son"?

One characteristic of modernist poetry is the use of symbolism. In "Mother to Son," the speaker uses lots of symbolism to convey her message to her son. For example, she tells her son twice that life for her "ain't been no crystal stair." The "crystal" here is a symbol of wealth and luxury, implying that the mother has lived a hard life of struggle rather than an easy, comfortable life. The mother also uses symbolism when she says that she has sometimes had to find her way "in the dark / Where there ain't been no light." The light is a common symbol in literature connoting clarity and hope. The mother is telling her son that sometimes one has to persevere in moments when nothing seems clear and everything seems hopeless.
Modernist poets also often experimented with form, and wrote, for example, in free verse. In free verse poetry, there is no rhyme scheme and no regular syllabic meter. Modernist poets chose this form of poetry in part because it gave a more natural, spontaneous feel to the poem. In "Mother to Son," Hughes writes in free verse. There is no rhyme scheme and no regular syllabic meter. This helps to give a greater authenticity to the voice of the speaker.