Parallel construction in pairs
Use parallel construction when a sentence contains a pair of connected ideas.
Pairs can be connected by coordinating conjunctions, which include and, nor, but, or and yet.
Not parallel
She planned to collect data by either using an online survey or phone interviews.
Parallel
She planned to collect data by either using an online survey or conducting phone interviews.
She planned to collect data through either online surveys or phone interviews.
Use parallel structure when a pair of ideas are linked by a correlative conjunction, such as not only...but also, either...or, and neither...nor.
Not parallel
His paper argues that the distinctive divergence in the two artists' styles was not only shaped by their mutual rivalry but also because of the idiosyncratic tastes of patrons.
Parallel
His paper argues that the distinctive divergence in the two artists' styles was shaped not only by their mutual rivalry but also by the idiosyncratic tastes of patrons.
The same rule applies to pairs connected by a word of comparison, such as over, than or as.
Not parallel
He prefers movie nights at home over going to loud house parties. He prefers movie nights at home over loud house parties.
Parallel
He prefers hosting movie nights at home over going to loud house parties.