Periodic sentence

A periodic sentence holds back the completion of its main idea until the final words, so the reader must take in every qualification first and the meaning only resolves at the full stop.

After the third lawyer, after the fourth set of forms, after a year of being told the file had been mislaid, she got the apology. Nothing resolves until the last three words. That is the shape: everything is suspension, and the sentence pays out at the end.

Three ways to build one.

• Front-load the dependent clauses. Because the road was closed and the ferry had stopped running, they walked.
• Stack initial modifiers. Soaked, furious, and out of excuses, he knocked.
• Delay the verb, or invert the usual order — see anastrophe.

The effect is tension, which makes it a natural fit for suspense and for the last sentence of a chapter. It is also the most emphatic structure English offers, because the end of a sentence is its strongest position and a periodic sentence spends everything on reaching it.

The cost is patience. A periodic sentence asks the reader to carry unresolved material, so a page of them is exhausting, and a long one that pays out on a weak word is worse than a plain sentence. Its opposite, the loose sentence, gives the point first and relaxes afterwards. Most good prose alternates, and saves the periodic shape for the sentence that matters.