Modifiers can be simple words or phrases or clauses. I think phrases and clauses trip up more writers except perhaps for nonnative English speakers.
A misplaced modifier isn’t close enough to what it is modifying. It’s too far away from the subject.
Example 1: She opened the door, frowning at him.
The door isn’t frowning—she is.
– It would be clearer like this: Frowning at him, she opened the door.
– If you want to indicate she frowned after she opened the door, there are several options: Opening the door, she frowned at him. OR She opened the door and frowned at him.
Sometimes a simple one-word misplaced modifier can make the meaning incorrect or confusing.
Example 2: In the drawer, I found a gold woman’s wedding ring.
The woman isn’t gold. In fact there is no woman.
– Correct: In the drawer, I found a woman’s gold wedding ring.
An ambiguous modifier can make the meaning unclear. Careful placement is required.
Example 3: Only Mark wanted to go to the store in town.
So, everyone else wanted to stay home. Right?
– But maybe it should be: Mark only wanted to go to the store in town.
He didn’t want to stop and get gas, too.
– But perhaps that wasn’t the writer’s intention: Mark wanted to go to the only store in town.
Each placement gives a different picture, doesn’t it? Commonly ambiguous modifiers include: almost, even, hardly, just, merely, nearly.
A dangling modifier has nothing in the sentence to modify. The intended subject is missing.
Example 4: Opening the cupboard door, it was full of mismatched teacups and saucers.
Who is opening the door? We don’t know.
– One possibility for correction would be to make it two separate sentences: He opened the cupboard door. Inside were mismatched teacups and saucers.
– Another possibility is adding who is doing the action: Opening the cupboard door, he poked around the mismatched teacups and saucers.
Notice I didn’t say: He opened the cupboard door and saw mismatched teacups and saucers. Describing what someone sees is not nearly so interesting as what they are doing with the objects.
A dangler often makes it appear that the wrong object is doing the impossible.
Example 5: Running upstairs, the carpet was dirty.
I’ve heard of carpet runners, but never actually saw a carpet run.
– Correct: The upstairs carpet was dirty.
– Also correct: I ran upstairs and picked my way across the dirty carpet.
I like this comment from examples.yourdictionary.com: “Modifiers are one of the most beautiful elements of the English language. They paint our prose and add starlight to our stanzas. Just make sure your modifiers are standing as close as possible to the word or words they’re describing. Otherwise, they may appear to be dressing up another portion of the sentence.”
If you want to test your recognition of dangling and misplaced modifiers, take this quiz. http://www.grammargrounds.com/misplaced-and-dangling-modifiers-quiz.html I like how the answers show which ones are misplaced and which ones are dangling.
And if you want to laugh at illustrations of misplaced modifiers, check out this slideshow: https://www.slideshare.net/Scribendi_Editing/12-hilarious-misplaced-modifier-examples.