What is the deliberate breaking of grammar rules for effect in "Ode to the West Wind," lines 1, 2 and 3?
In Ode to the West Wind by Percy Bysshe Shelley, many poetical variations to grammar are employed for economy and impact of expression, some of which is accomplished by changing the normal pattern of emphasis. For instance, in lines 2 and 3, Shelley inverts an adjectival position and alters the normal English sentence word order of SVO.
In line 1, Shelly constructs an apostrophe that is followed by an appositive that follows its noun or noun phrase, which is "Wind" or "wild West Wind." An apostrophe is an interruption that addresses a person or personified thing (nonhuman) as though it were present (and human). This poetical variation device might also be grammatically rewritten as, "Thou breath of Autumn's being, O wild West Wind," with the noun phrase in front of the appositive being "Autumn's being."
In line 2, Shelley has inverted the grammatical noun phrase order of article-adjective-noun to place the adjective in "leaves dead" behind the noun instead of in front of it. The noun phrase would grammatically read "the dead leaves" instead of Shelley's poetically turned "the leaves dead."
In line 3, Shelley alters normal word order of SVO (Subject Verb Object) and puts the Verb "flee" at the end of the Object "an enchanter." The normal grammatical word order of this subordinate clause (conjunction "like") would be "like ghosts fleeing from an enchanter." The matrix clause is "the dead leaves are driven."