Parallel Structures

Parallelism in multi-clause sentences

Sometimes the non-parallel elements in a sentence are in the same clause. However, the biggest difficulty is that in academic writing, you have to write longer, multi-clause, complex sentences. Unfortunately, you may sometimes writee sentences in which every clause on its own is correct, but together the clauses are not parallel.

Consider:

HIV infection rates in poorer countries are increasing as a result of three main factors, namely the mass migration of labourers from rural areas, many people are ignorant about safe sexual practices and many young girls in the Third World are poor and turn to prostitution.

This sentence is not parallel because the first clause the mass migration of labourers from rural areas is a noun phrase, but the second two are verb phrases. This shows that you need to check that all three factors are expressed in the same form (e.g. all nouns, all verbs or all adjectives). Changing the verb phrases into noun phrases would correct the non-parallel structure and also make this sentence more concise and easy to read (changing verb phrases into noun phrases is called nominalisation – refer to this page).

Consider the corrected sentence:

HIV infection rates in poorer countries are increasing as a result of three main factors, namely the mass migration of labourers from rural areas, ignorance about safe sexual practices and poverty, which forces young girls in the Third World to turn to prostitution.

The sentence is now correct, parallel and is concise. It also looks well written and is academic.