Tutoring high school and college English, you mention parallelism.  The tutor introduces it.

Non-parallel:  I like drawing, reading, and to play the piano.

Parallel:         I like drawing, reading, and playing the piano.

Let’s compare the two examples above.  In the Parallel one, all the speaker’s activities are listed in the same form; therefore, parallelism is achieved. In the Non-parallel one, drawing  and reading are in -ing (gerund) form, while to play is in infinitive form.

Parallel structures are parts of a sentence that have similar construction.  What creates parallelism is the way those parts are written rather than their meaning.

In the academic world, parallelism is viewed fondly –  failure to execute it, disapprovingly. Last I heard, English 12 government exams are marked with consideration for parallel structures.  A sentence like the “Non-parallel” example above would likely receive a deduction for “faulty parallelism.”

While English is mainly about content, markers like style as well.  A few nice touches – like parallelism – can elevate a teacher’s perception of a paper from “good” to “very good”, or from “very good” to “great.”  Hopefully, that paper will be yours:)

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.