We should always try to communicate as clearly and precisely as we can to minimise the amount of work the reader has to do to decode the language. One of the things that can confuse a reader is faulty parallelism.
Faulty parallelism occurs when related items in a sentence have different grammatical structure and form. We often find this error in sentences containing lists.
How does this sentence sound to you?
Nora likes running, hike and to camp
You can probably hear that there is something wrong here. In this sentence, we find three listed elements, but they all have different forms:
- running
- hike
- to camp
The first one uses the -ing form (or the progressive form), the second uses the infinitive form without ‘to’, and the last uses the full infinitive form – to camp. This sentence needs more balance, and we can create this balance in two ways:
Nora likes running, hiking, and camping
OR
Nora likes to run, hike, and camp
Both of these sentences have parallel structures, i.e. the same form of the verb has been used throughout the sentence. By using words that share the same grammatical structure, it creates a sense of rhythm and balance within the sentence. It sounds less awkward and not as poorly constructed, and it enables the reader to focus on the main idea of the sentence, rather than how the sentence has been put together.
Let's look at another example. What is wrong with this sentence?
My English teacher was informative, funny, and a source of inspiration.
This sentence also contains a list of three elements:
- informative
- funny
- a source of inspiration.
As in the first sentence, the three elements do not have the same grammatical function. 'Informative' and 'funny' are both adjectives, while 'a source of inspiration' is a noun phrase.
To repair the faulty parallelism in this sentence, you will have to change the last element – a 'source of inspiration' – into an adjective:
My English teacher was informative, funny, and inspiring.
Now you have a parallel construction, where all three elements use the same grammatical structure.
Here are a few more examples:
Incorrect: He admitted to robbing the bank and that he escaped in a black car.
Correct: He admitted to robbing the bank and escaping in a black car.
Incorrect: This is not a time for words, but action.
Correct: This is not a time for words, but for action.
Incorrect: The waiter suggested lamb chops, green beans and that we try the sweet potatoes.
Correct: The waiter suggested lamb chops, green beans, and sweet potatoes.
Before you move on to the tasks, this video from Khan Academy may clarify the matter further:
Link to Parallel Structure: Khan Academy