The misplaced modifier is a type of grammatical mistake that is fairly common in English.

English is a flexible language that affords a writer or speaker multiple ways to express a given idea. The order in which concepts occur in a sentence, for example, usually has little or nothing to do with what the sentence means. So, you mean the same thing whether you say:

"Because I love you, I will marry you."

or

"I will marry you because I love you."

This sort of flexibility makes for a rich array of possible structures in speech and writing in English. But it also creates situations where it is not clear what is being communicated. One type of confusing writing involves uncertainty regarding what "thing" a clause modifies.

Example of misplaced modifier: 1.Stacked eight bales tall against the autumn sky, the farmer leaned against the hay and admired the crops.

Stacked eight bales tall against the autumn sky (modifier, or modifying clause), the farmer (the object actually modified) leaned against the hay (the object the writer means to modify) and admired the crops.

The way the above sentence is written, it is the farmer, not the hay, that is stacked "eight bales tall."

What that sentence should say, and means to say, is:

The farmer leaned against the hay, stacked eight bales tall against the autumn sky, and admired the crops.

Now there is no confusion. The modifying clause, "stacked...tall," is placed correctly in this second example, and it is clear what is stacked, and what is not.