Poem help? "life for me ain't been no crystal stair" in that line a poetry, is there any assonance or is there a metaphor? if so where?

Assonance is the repetition of vowel sounds...metaphor is a comparison. Life is being compared to a crystal stair. It's a metaphor. In this poem, Langston Hughes uses an extended metaphor to compare the woman's life to stairs she had to battle to climb. They had tacks, splinters, torn up boards, no carpet, and twists and turns which made her path difficult. It is about a mother telling her son that no matter how hard life can be, never stop climbing upward.