A modifier is a word or phrase that describes something else in a sentence. A dangling modifier is one whose target is missing, so the reader attaches it to whatever comes next, often with comic results:
- Walking to work, the rain started. The rain was not walking to work.
- After finishing the report, the coffee machine was empty. The coffee machine did not finish the report.
- Having been fed, the zookeeper closed the cage. Presumably it was the animals that were fed.
When the modifier is built on a participle (walking, having been fed), it is also called a dangling participle.
Why it happens
English readers expect an opening phrase to describe the subject that follows the comma. Walking to work, I ... sets up "I" as the walker. When the subject turns out to be something else, the phrase is left hanging. Writers produce these because the person doing the action is obvious to them; it is simply not on the page.
Two ways to fix it
1. Make the doer the subject
Keep the opening phrase and put the person or thing it describes straight after the comma:
- Walking to work, I got caught in the rain.
- After finishing the report, Maria found the coffee machine empty.
2. Turn the phrase into a full clause
Give the opening phrase its own subject, and the main clause can stay as it was:
- While I was walking to work, the rain started.
- After Maria finished the report, the coffee machine was empty.
Dangling versus misplaced
A misplaced modifier is a close relative: its target is in the sentence, but the modifier sits next to the wrong word.
- She served sandwiches to the guests on paper plates. Were the guests on the plates? Better: She served the guests sandwiches on paper plates.
- I only eat fish on Fridays and I eat fish only on Fridays mean different things. Small words like only, just, almost and nearly modify what they stand next to, so put them beside the word you mean.
The fix for a misplaced modifier is to move it; the fix for a dangling one is to add what is missing.
How to spot them
Look at every sentence that opens with a phrase and a comma, especially one starting with an -ing word, having, after, before, while or when. Ask who is doing the action in the opening phrase, then check that this is the first noun after the comma. If it is not, rewrite.
How the spell checker helps
A dangling modifier is made of correctly spelled words in a grammatical order, so neither a spelling check nor a rule-based grammar check can be relied on to see it: the problem is in the meaning. Run the Spell Checker for the mistakes it can find, try the AI Spell Checker for a reading in context, and give opening phrases the "who is doing this?" test yourself.