what is parrallel structure?

Parallel structure is making sure that all parts of a series or other sentence constructions are using nouns, verbs, adjectives, etc., in the same order. There are some excellent examples here:

http://grammar.ccc.commnet.edu/grammar/parallelism.htm
Be sure to scroll down to see the examples (in a chart).

http://leo.stcloudstate.edu/grammar/parallelism.html

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