‘Parallel structure’ or ‘parallelism’ refers to keeping the same grammatical structure in your writing when you list items in a series.

Mistakes are very common in this area. They make your writing look and sound clunky and can impede a reader’s understanding. Here’s a simple example:

WRONG
Top Energy is a company that produces and delivers heat and water supplies and also sewage disposal.

RIGHT
Top Energy is a company that produces and delivers heat and water supplies and also disposes of sewage.

In this example “sewage disposal” is a noun phrase while “disposes of sewage” is a verb phrase. The sentence needs a verb phrase here because the other two items in the series – “produces and delivers heat” and “(produces and delivers) water supplies” – are verb phrases. In order to be parallel, the third item on the list must use the same grammatical structure as the other items.

Here’s another example:

WRONG
If the owner of the premises breaches the agreement, the association of premises’ owners may demand from the owner the removal of the breach and restore the property to its original condition.

RIGHT
If the owner of the premises breaches the agreement, the association of premises’ owners may demand from the owner the removal of the breach and the restoration of the property to its original condition.

In this example the first item listed is “the removal of the breach”, which is a noun phrase. The second item listed is “restore the property to its original condition” – a verb phrase. To make the second item parallel, I have turned it into a noun phrase – “the restoration of the property to its original condition”.

This mistake is particularly bad because it changes the meaning of the sentence. I can illustrate this by making bullet points of the listed items. Here’s the correct version:

If the owner of the premises breaches the agreement, the association of premises’ owners may demand from the owner

• the removal of the breach and
• the restoration of the property to its original condition.

Note how the two bulleted items are parallel noun phrases.

Now here’s how the incorrect version could be misunderstood (where the two bulleted items are parallel verb phrases):

If the owner of the premises breaches the agreement, the association of premises’ owners may

• demand from the owner the removal of the breach and
• restore the property to its original condition.

Instead of the owner having to restore the property to its original condition, the association does it.

Such a misunderstanding can arise because readers expect listed items to be parallel.

The technique of making bullet points of listed items is very useful when trying to understand more complex sentences. Have a look at this example:

Participants in this conference will have an opportunity to learn how to determine employment status, properly structure an employment contract and what are the typical elements of employee compensation and benefits packages offered in Poland and Hungary and the legal issues related to them.

If we make a bullet-pointed list, this is what we get:

 Participants in this conference will have an opportunity to learn how to

• determine employment status,
• properly structure an employment contract and
• what are the typical elements of employee compensation and benefits packages offered in Poland and Hungary and the legal issues related to them.

The third item is not parallel. The first two items are verb phrases which grammatically follow the introductory sentence. The third item is ungrammatical when read together with the introductory sentence. There are various ways to correct this sentence, but, as it is a long sentence, I suggest splitting it into two sentences as follows:

Participants in this conference will learn how to determine employment status and properly structure an employment contract. The conference will also cover the typical elements of employee compensation and benefits packages offered in Poland and Hungary and the related legal issues.

Although bullet-pointed lists are very useful in this context, faulty parallelism can still creep into them. Consider this example:

WRONG
With reference to the Company’s planned share capital decrease, please find attached a power of attorney authorising us to represent the Company’s sole Shareholder at the Company’s Extraordinary Shareholders’ Meeting and vote for and on behalf of the Shareholder on matters related to:

• decreasing the Company’s share capital,
• amendment of its Articles of Association,
• adoption of the unified text, and
• any other matters on the Agenda of the Extraordinary Shareholders’ Meeting related to the share capital decrease.

RIGHT
With reference to the Company’s planned share capital decrease, please find attached a power of attorney authorising us to represent the Company’s sole Shareholder at the Company’s Extraordinary Shareholders’ Meeting and vote for and on behalf of the Shareholder on matters related to:

• decreasing the Company’s share capital, OK
• amending its Articles of Association,
• adopting the unified text, and
• any other matters on the Agenda of the Extraordinary Shareholders’ Meeting related to the share capital decrease. OK

The first bullet point “decreasing the Company’s share capital” is a gerund phrase. (A gerund is an –ing form that acts like a noun.) In the above corrected version I have made the second and third bullets into gerund phrases so they are parallel to the first. As gerund phrases behave like noun phrases, the fourth bullet (being a noun phrase) is OK.

It is also possible to make all the bullets noun phrases, as below. Note the addition of the to the second and third bullets, which was missing in the original version:

RIGHT
With reference to the Company’s planned share capital decrease, please find attached a power of attorney authorising us to represent the Company’s sole Shareholder at the Company’s Extraordinary Shareholders’ Meeting and vote for and on behalf of the Shareholder on matters related to:

• the decrease of the Company’s share capital,
• the amendment of its Articles of Association,
• the adoption of the unified text, and
• any other matters on the Agenda of the Extraordinary Shareholders’ Meeting related to the share capital decrease. OK

Another problem related to parallel structure involves the use of prepositions. Have a look at this example:

WRONG
Employees have the right to subscribe and benefit from a certain percentage of shares.

 RIGHT
Employees have the right to subscribe to and benefit from a certain percentage of shares.

Although you can benefit from something, you cannot subscribe from something. You subscribe to something.

Another example:

WRONG
The Agency intends to engage the Company to provide equipment, and the Company confirms that it is willing to and capable of providing the equipment.

Here, capable of providing is correct, but willing to providing is wrong.

RIGHT
The Agency intends to engage the Company to provide equipment, and the Company confirms that it is willing to provide the equipment and capable of doing so.

The Agency intends to engage the Company to provide equipment, and the Company confirms that it is willing and able to provide the equipment.

In the second correct version, willing to and able to both take the infinitive (provide), so only one preposition (to) is required.