Parallelism refers to using elements in sentences that are grammatically
similar or identical in structure, sound, meaning or meter. This
techniques adds symmetry, effectiveness and balance to the written
piece.
Compare the following examples:
Lacking parallelism: She likes singing, dancing, and to read.
Lacking parallelism: He likes to jog and running.
Parallel: She likes singing, dancing and reading.
Parallel: She likes to sing, dance, and read.
Parallel: He likes to jog and run.
Parallel: He likes jogging and running.
In the above...