This study guide summarizes topics that Spanish IV students often struggle with for their final exam, including the imperfect subjunctive, por y para, and formal and informal commands. The imperfect subjunctive is used in conditional sentences and with certain verbs like deber and querer to make polite requests. Por is used for reasons like "by" or "during" while para indicates recipients, deadlines, destinations, purposes and opinions. Commands are formed by taking the yo form and changing the ending based on whether it is formal or informal. Examples are provided for each topic.