Parallelism in English refers to using similar grammatical structures, such as words, clauses, phrases, or sentence structure, to emphasize similar ideas in a sentence. The purpose of parallelism is to make writing more effective, clear, and interesting, and to link related ideas and emphasize the relationships between them. Faulty parallelism refers to the absence of parallel structure, which can lead to a loss of clarity.

Examples of parallelism include:

• Using parallel structure when connecting ideas with a coordinating conjunction (paired items)
• Using parallel construction when items in a series have an equal level of importance
• Grouping nouns with other nouns, adjectives with other adjectives, and so on
• Using the same verb, noun, adverb, or adjective forms consistently throughout a sentence

Examples of faulty parallelism include:

• Mixing forms when a series is composed of verbs
• Using different grammatical structures for related words, phrases, or clauses in a sentence or a paragraph

By using parallelism, writers can make their writing more effective and clear, and emphasize the relationships between ideas.