Mixed Constructions

A mixed construction combines two or more incompatible sentence parts or grammatical structures in the same sentence, resulting in a sentence that is either grammatically or logically flawed. The key to avoiding mixed constructions is always to be consistent in person, number, tense, mood, voice, and tone. You do not, as the old saying goes, want to change horse in midstream.

Below are common examples of mixed constructions and advice on how to remedy these errors.

Person

	While the Rangers are infantry, they are designated as SOF, which gives you certain advantages.
	While the Rangers are infantry, they are designated as SOF, which gives them certain advantages.

Number

Number refers to the number of subjects and objects involved in the sentence. For example, to begin by referring to several soldiers and then refer to them as "he" constitutes a mixed construction.

	At the end of the third year, if they wish to continue with the military past the end of their bachelor's degree, a Junior Under-Officer may proceed to the Royal Military Academy at Sandhurst, where he takes his TA Commissioning Course.
	At the end of the third year, if they wish to continue with the military past the end of their bachelor's degree, Junior Under-Officers may proceed to the Royal Military Academy at Sandhurst, where they take their TA Commissioning Course.

Tense

Tense refers to when a certain action takes place. To cast an event in the past tense and then speak of the same event in the present would constitute a mixed construction.

	The human side of leading aviators into combat has indeed been studied, but most of that work is done by historians.
	The human side of lMeading aviators into combat has indeed been studied, but most of that work has been done by historians.

Voice

There are two main voices: active (the subjects acts) and passive (the subject is acted upon). Active and passive voice should not be mixed in the same sentence. [For further understanding of the distinction between the two voices, see Active vs Passive Voice.]

	It is unfortunate in some ways that, following the advice of their superiors, officers put [active] more effort toward obtaining a degree, and less attention is given [passive] to obtaining an education.
	It is unfortunate in some ways that, following the advice of their superiors, officers put [active] more effort toward obtaining a degree and give less attention [active] to obtaining an education.

Mood

There are three main moods: indicative (stating a fact or making an assertion), imperative (giving a command), and subjunctive (expressing a doubtful or conditional point). Changing moods within a sentence results in a mixed construction.

	If Canada were to get its voice into the international community [subjunctive], there is no better multilateral forum in the current international system for this country to join than NATO [indicative].
	If Canada were to get its voice into the international community, there would be no better multilateral forum in the current international system for this country to join than NATO. [Both parts of the sentence are in the subjunctive mood.]

Tone

Shifts in tone are perhaps more difficult to detect than those in mood. Like mood, tone refers to the speaker's attitude toward the subject or the audience. Tone can be discerned through a combination of the author's word choices, adjective and word selection, sentence structure, mood, and voice. [For further understanding, see Tone and Voice.]

	Though spoken in a defense context and during a world geopolitical climate vastly different than that of the present, Mr. Trudeau's statement in 1968 concerning realism in our attitude toward international policy is handy and pretty easy to follow. [The underlined phrase has an informal, colloquial tone that is in contrast to the formal language in the first part of the sentence.]
	Though spoken in a defense context and during a world geopolitical climate vastly different than that of the present, Mr. Trudeau's statement in 1968 concerning realism in our attitude toward international policy displays a timeless quality that is enviable in its simplicity. [The tone of the underlined phrase is in keeping with the formal language of the sentence.]

Help! Mixed constructions can occur both within a sentence and within and between paragraphs. If you adopt a particular tone, for example, be careful to maintain that tone throughout your piece of writing.