Basic Principle: Modifiers are like teenagers: they fall in love with whatever they're next to. Make sure they're next to something they ought to modify!
MISPLACED MODIFIER: Some modifiers, especially simple modifiers only, just, nearly, barely have a bad habit of slipping into the wrong place in a sentence. (In the sentence below, what does it mean to "barely kick" something?)
|Confusion||He barely kicked that ball twenty yards.|
|Repair Work||He kicked that ball barely twenty yards.|
The issue of the proper placement of "only" has long been argued among grammarians. Many careful writers will insist that "only" be placed immediately before the word or phrase it modifies. Thus "I only gave him three dollars" would be rewritten as "I gave him only three dollars." Some grammarians, however, have argued that such precision is not really necessary, that there is no danger of misreading "I only gave him three dollars" and that "only" can safely and naturally be placed between the subject and the verb. The argument has been going on for two hundred years.
DANGLING MODIFIER: When we begin a sentence with a modifying word, phrase, or clause, we must make sure the next thing that comes along can, in fact, be modified by that modifier. When a modifier improperly modifies something, it is called a "dangling modifier." This often happens with beginning participial phrases, making "dangling participles" an all too common phenomenon. In the sentence below, we can't have a car changing its own oil.
|Confusion||Changing the oil every 3,000 miles, the car seemed to run better.|
|Repair Work||Changing the oil every 3,000 miles, Fred found he could get much better gas mileage.|
A participial phrase followed by an Expletive Construction will often be a dangling participle but the expletive construction is probably not a good idea anyway. This faulty sentence can be remedied by changing the participial phrase into a full-fledged clause with a subject and verb.
|Confusion||Changing the oil every 3,000 miles, there is an easy way to keep your car running smoothly.|
|Repair Work||If we change the oil every 3,000 miles, we can keep our car running smoothly.|
A participial phrase followed by a Passive Verb is also apt to be a dangler because the real actor of the sentence will be disguised.
|Confusion||Changing the oil every 3,000 miles, the car was kept in excellent condition.|
|Repair Work||Changing the oil every 3,000 miles, we kept the car in excellent condition.|
An infinitive phrase can also "dangle." The infinitive phrase below should probably modify the person(s) who set up the exercise program.
|Confusion||To keep the young recruits interested in getting in shape, an exercise program was set up for the summer months.|
|Repair Work||To keep the young recruits interested in getting in shape, the coaching staff set up an exercise program for the summer months.|
SQUINTING MODIFIER: A third problem in modifier placement is described as a "squinting modifier." This is an unfortunate result of an adverb's ability to pop up almost anywhere in a sentence; structurally, the adverb may function fine, but its meaning can be obscure or ambiguous. For instance, in the sentence below, do the students seek advice frequently or can they frequently improve their grades by seeking advice? You can't tell from that sentence because the adverb often is "squinting" (you can't tell which way it's looking). Let's try placing the adverb elsewhere.
|Confusion||Students who seek their instructors' advice often can improve their grades.|
|Repair Work||Student who often seek their instructors' advice can improve their grades.|
|Repair Work||Students who seek their instructors' advice can often improve their grades.|
See the section on Sentence Variety for definitions and examples of Summative and Resumptive Modifiers.