Answer:
No, Whitman does not use rhyme to convey his important ideas on the universal communication of grass in the poem "A child said What is the grass?"
No, Whitman does not use alliteration in lines 13-18 to reiterate his love of old and young people in the poem "A child said What is the grass?"
Yes, Whitman uses rhythm in line 3 as a way to add emphasis to his view of grass in the poem "A child said What is the grass?"
Yes, Whitman uses repetition to emphasize how grass is both universal and personal for all people in the poem "A child said What is the grass?"