Regarding sentence structure in English, analyze the following statements and select the CORRECT alternative.
I. In affirmative sentences in English, the usual word order is Subject + Verb + Object, which is rarely altered to emphasize another element.
II. To form questions in English, auxiliary verbs like "do," "does," and "did" are commonly used, except in present simple and past simple questions, where they are unnecessary.
III. In negative sentences in English, the particle "not" is often used in combination with auxiliary verbs but can also be directly applied to main verbs without altering the structure.
IV. The inversion of subject and verb is a common feature in questions and in some constructions with adverbs like "rarely" and "seldom."