A participle is a form of a verb. English has two types of participles: present participles and past participles. Present participles are easy to identify: they end in –ing.
For instance, “speed” is a verb, and “speeding” is its present participle. To use “speeding” as an adjective-like participle, you could say “Follow that speeding car.”
Phrases that contain a participle and modify the subject of the sentence are called “participial phrases.” ex: “Looking around, I was the only one driving an American car.”
“Looking around” is the participial phrase. The present participle (‘looking’) refers to the subject of the main clause (the pronoun ‘I’) – ‘I’ is the speaker or writer and the person who is both looking around and driving an American car, so everything matches up.
The participial phrase doesn’t have to be at the beginning of a sentence, but it often is –and that is the place where it’s most likely to dangle. When you dangle a participle, it means your participial phrase is hanging there in your sentence with no proper subject in sight.
For example, “Hiking the trail, the mosquitoes buzzed incessantly.”
The mosquitoes are the only subject in the sentence, and they directly follow the participial phrase. The participial phrase has to grab on to something to modify, so it grabs the only subject — the mosquitoes. So what that sentence says is that the mosquitoes were hiking the trail, and that’s probably not what was meant. There’s probably somebody hiking the trail and hearing the mosquitoes buzzing incessantly.
We can fix it by adding the proper subject right after the participial phrase: “Hiking the trail, the boys heard mosquitoes buzzing incessantly.”
Another example: “Walking along the passage to the town, a police barrier blocked our way”
What is the subject of the above sentence? It’s the noun performing the action of the main verb; here, the main verb is “blocked,” and the thing that’s doing the blocking and therefore the sentence’s subject is “a police barrier.”
Now, we know that a police barrier can’t possibly be “walking along the passage,” so we have a dangling participle here. We need to rewrite the sentence: “Walking along the passage to the town, we found that our way was blocked by a police barrier.”
The sentence has been changed to make “we” the subject, which matches the participle ‘walking’ in the preceding clause. All is now clear.
So to sum up, a dangling participle modifies the wrong noun.
You fix a dangling participle by putting the proper subject in the sentence, usually right after the participle or participial phrase.