Definition:
In literature, the concept of a periodic structure refers to a particular placement of sentence elements such as the main clause of the sentence and/or its predicate are purposely held off and placed at the end instead of at the beginning or their conventional positions. In such placements, the crux of the sentence’s meaning does not become clear to the reader until they reach the last part. While undeniably confusing at first, a periodic structure lends a flair of drama and romanticism to a sentence and is greatly used in poetry.
Example:
Instead of writing, “brokenhearted and forlorn she waited till the end of her days for his return” one may write, “for his return, brokenhearted and forlorn, waited she till the end of her days”.