Parallel words
On the word level, a noun should be grouped with other nouns, an adjective with other adjectives, and so on.
Not parallel
The company is looking for a candidate who is friendly, organized, meticulous, and is going to arrive to work on time.
Parallel
The company is looking for a candidate who is friendly, organized, meticulous, and punctual.
When a series is composed of verbs, do not mix forms. For example, mixing an infinitive (a verb beginning with to) with a gerund (a verb form ending in -ing) breaks parallel structure.
Not parallel
The participants in the workshop learned how to communicate, negotiate, and working collaboratively for the most effective outcome.
Parallel
The participants in the workshop learned how to communicate, negotiate, and work collaboratively for the most effective outcome.
The participants in the workshop learned about communicating, negotiating, and working collaboratively for the most effective outcome.