Coherence is the principle of composition that requires that, for the sake of clari-
ty, words and ideas follow one another in an orderly manner and that the connec-
tions be-tween parts be made clear.
If there is a reasonable chance that the relationship between words and ideas may
be mistake, the sentence, paragraph, or theme is incoherent.
Clearness in writing is largely a matter of unity, coherence, and emphasis. It is
necessary, of course, that the writer's ideas be clear to begin with. But unity, co-
herence, and emphasis go far to make sure that these ideas will also become clear
to the reader.
What unifies a composition often makes it coherent and lends it proper emphasis —
and vice versa. Hence there is a certain amount of overlapping in fact and in rule.
Coherence in the sentence
Coherence in the sentence means that the parts of a sentence — words, phrases, and
clauses — are rightly put together.
The principal enemies of coherence in the sentence are misplaced, squinting, and
dangling modifiers; unparallel structure for parallel ideas; faulty connectives and
connections; and illogical expressions.
(Modifiers that seem to modify the wrong word or no word at all are called dangling
modifiers.
Misplaced modifiers are modifiers so placed in a sentence that they seem to modify
the wrong word.
Squinting modifiers — often adverbs — are modifiers so placed that they seem to
modify either of two expressions.)
Where you can do so without forcing or awkwardness, express like ideas in like
words and like constructions.
Keep sentence parts parallel when they are joined by and, or, nor, but , 
and other co-
ordinating conjunctions.
Do not use and, or, nor, but, and other coordinating conjunctions between sentence
parts that are not parallel in thought.
Do not shift the idea in the subject needlessly.
Do not shift voice needlessly.
Do not shift person or number needlessly.
Do not shift present and past time needlessly.
Use connectives that express your meaning precisely.
Do not omit a word that is important to the clear and easy expression of your
thought.
Phrase your sentences thoughtfully and logically so that they make sense and can
have only one meaning.
