An example of faulty parallelism is "Mary likes to dance, sing and reading books." Faulty parallelism occurs when a sentence uses mixed forms of words with similar importance. One way to correct the sentence is to write "Mary likes to dance, sing and read books."
Faulty parallelism can occur with phrases, words or clauses. It is sometimes used by writers who believe they must always vary their expressions. However, parallel construction is grammatically correct and creates sentences with better flow.
Another example of faulty parallelism can occur when the writer is making comparisons. For example, the sentence "John's income is larger than Anne" has faulty parallelism. A correct sentence is "John's income is larger than Anne's."