A dangling modifier is one that does not modify any element of the sentence in which it appears. A misplaced modifier is one that makes the sentence ambiguous because it is placed too far from the thing it modifies or too near to something else that it could modify.

The most common error of this type is a participial or infinitive phrase at the beginning of a sentence that does not refer to the subject. If the main clause is in passive voice, it is easy to overlook the lack of connection between modifier and subject.

To correct a dangling modifier, either change the subject of the sentence or change the modifying phrase into a clause so that its referent is clear.

For more information, see Harbrace College Handbook and Handbook of Technical Writing.

Microsoft style

By using object-oriented graphics, you can edit each element of the graphic because the structural integrity of the individual elements is maintained.

Even when you add more data, the spreadsheet calculates as quickly as before.

To add original graphics to your document, you need a scanner.

Not Microsoft style (dangling modifiers)

By using object-oriented graphics, the structural integrity of the individual elements of the graphic is maintained and can be edited.

Even after adding more data, the spreadsheet calculates as quickly as before.

To add original graphics to your document, a scanner is needed.

To correct a misplaced modifier, move the modifier so that it clearly, unambiguously modifies the thing you intend.

Microsoft style

There are files that cannot be removed on the disk.

Misplaced modifier (misplaced modifier)

There are files on the disk that cannot be removed.