Of course in simple sentences the natural order of arrangement is subject—verb—object. In many cases no other form is possible. Thus in the sentence "The cat has caught a mouse," we cannot reverse it and say "The mouse has caught a cat" without destroying the meaning, and in any other form of arrangement, such as "A mouse, the cat has caught," we feel that while it is intelligible, it is a poor way of expressing the fact and one which jars upon us more or less.
In longer sentences, however, when there are more words than what are barely necessary for subject, verb and object, we have greater freedom of arrangement and can so place the words as to give the best effect. The proper placing of words depends upon perspicuity and precision. These two combined give style to the structure.
Most people are familiar with Gray's line in the immortal Elegy—"The ploughman homeward plods his weary way." This line can be paraphrased to read 18 different ways. Here are a few variations:
Homeward the ploughman plods his weary way.
The ploughman plods his weary way homeward.
Plods homeward the ploughman his weary way.
His weary way the ploughman homeward plods.
Homeward his weary way plods the ploughman.
Plods the ploughman his weary way homeward.
His weary way the ploughman plods homeward.
His weary way homeward the ploughman plods.
The ploughman plods homeward his weary way.
The ploughman his weary way plods homeward.
and so on. It is doubtful if any of the other forms are superior to the one used by the poet. Of course his arrangement was made to comply with the rhythm and rhyme of the verse. Most of the variations depend upon the emphasis we wish to place upon the different words.
In arranging the words in an ordinary sentence we should not lose sight of the fact that the beginning and end are the important places for catching the attention of the reader. Words in these places have greater emphasis than elsewhere.