The Basics of Ambiguous (Squinting) Modifiers

Ambiguous (“Squinting”) modifiers

Listening to loud music slowly gives me a headache.

When I listen to loud music, I slowly develop a headache.

A squinting modifier is a misplaced modifier that, because of its location in a sentence, could modify either the phrase that precedes it or the one that follows it. (In the example sentence, is the subject listening to music slowly or slowly getting a headache?) To correct a squinting modifier, reposition it in the sentence to make it clear to the reader which word you intend to modify.

from Grammarly Blog
http://www.grammarly.com/blog/2015/the-basics-of-ambiguous-squinting-modifiers/