In the sentence pattern for asking questions, the subject is placed immediately after the operator (Operator [did, does, was] + Subject) while in the sentence pattern for making statements, the subject is placed before the verb phrase (Subject + VP). However, some statements may be in question form (You've already eaten?) and some questions (such as rhetorical ones) may be in statement form (Haven't you peed already?).
It is independent because it expresses a complete tought.
<span>So that you are guaranteed to catch a reader's eyes in your paragraph.</span>