The document provides an overview of common types of grammatical errors involving modifiers: 1) Parallelism errors occur when grammatically different components are used in a list. 2) Dangling modifiers are phrases that do not logically modify any words in the sentence. 3) Squinting modifiers are words placed ambiguously to modify a preceding or following word. 4) Misplaced modifiers are words or phrases improperly separated from the words they modify, causing sentences to sound awkward or illogical. Examples of each type of error are given.