Items involving parallel structures

In certain structure items, the correct use of parallel structures is tested. Parallel structures have: the same grammatical form and function. Look at the following sentences:

She spends her leisure time hiking, camping, and fishing.

He changed the oil, checked the tire pressure, and filled the tank with gas.

Nancy plans to either study sociology or major in sociolinguistics.

Nancy plans to study either medicine or biology.

All of the structures in italics are parallel. In the first, three gerunds are parallel; in the second, three main verbs; in the third, two simple forms; and in the fourth, two nouns. Many other structures may be parallel in certain sentences: adjectives, adverbs, infinitives, prepositional phrases, noun clauses, and others.

The most common situation in which parallel structures are required is in a sequence in the first two sentences above. Parallel structures are also required with correlative conjunctions such as either...or, not only...but also, both...and, as well...as.

Examples:

Yalta has not only a pleasant climate, (but also exciting scenery/ but also has exciting scenery/ but also the scenery is exciting/but the scenery is also exciting), and many fascinating neighborhoods.

Until recently, most of the research on intercultural communication has focussed on native /non-native speaker interaction (both in the context of immigration and minorities and/either in the context of immigration and minorities or/not only in the context of immigration minorities but also) in intercultural politics and business..