Parallel sentence also known as parallel structure is the repetition of a chosen grammatical form within a sentence.
Parallel structure is achieved by making each compared/listed item or idea in your sentence follow the same grammatical pattern.
Noun/Pronoun — Noun/Pronoun
She is my friend and mentor .
(wrong: She is my friend and mentors me.)
John Mark is smart and diligent .
(wrong: John Mark is smart and works hard.)
The children ran and hid behind the tree.
(wrong: The children ran and were hiding behind the tree.)
You cannot be here and there at the same time.
(wrong: You cannot be here and go there at the same time.)
Wearing a dark jacket and hiding in the shadows the man sneaked into the building.
(wrong: Wearing a dark jacket and to hide behind the shadows the man sneaked into the building.)
You can choose to fail or to succeed .
(wrong: You can choose to fail or be successful .)
There are two kinds of people in the world: those who cheat and those who are cheated .
I admire people whose minds are active and whose hearts are pure.