An inverted sentence is one in which the normal order of a subject followed by a verb is reversed. A question is the most common type of sentence that is inverted. Often, an inverted sentence begins with a word that deserves emphasis, such as a negative or time-constraining phrase. With the order of the words taking an unusual form in the inverted sentence structure, it is important for the subject to be properly identified so that the subject and verb agree in number.
In some languages, the word order of a question might not be inverted, and voice intonation could indicate the interrogative. A question in English, however, often is constructed with a verb first. For example, one could ask the question, "Are you going to school?" An alternative form without the verb first would be, "You're going to school?" with the voice rising to indicate a question.
Sentences that begin with time-constraining words or phrases, such as "rarely," "hardly ever" and "never," normally are inverted. A sentence that is constructed this way puts emphasis on the rarity or impossibility of the action, such as "Rarely do I get my wife's approval." This structure also can be used to emphasize a conditional constraint, such as with the phrases "not only" and "not until."
A conditional sentence with the "if" omitted can best be expressed in an inverted form. As an example, "If I were sick, I'd miss school" would be constructed as "Were I sick, I'd miss school." This construction is considered somewhat formal and stiff.
Many sentences can be inverted if they begin with a subordinate clause. The most common clauses introducing an inverted sentence indicate a place. "Under the bridge lived a nasty troll" and "Above the school waved a flag" are examples.
Subordinate clauses also can be inverted and, like sentences, can convey some measure of emphasis that would not be present in the absence of the inversion. This structure sometimes substitutes for one in which a clause would be connected by a conjunction to the main thought. One example is, "The audience was silent at the curtain call, so bad was the performance." The normal sentence structure would be, "The audience was silent at the curtain call because the performance was so bad."
One should pay close attention to number agreement between subject and verb in an inverted sentence. "From the rooftop hang three flags," is an inverted sentence with "flags" as the subject. Thus the verb "hang" must have a plural form. It might be easy to mistake "rooftop" for the subject of this sentence and use the singular form of the verb.