How do I use the imperfect subjunctive in Spanish?

The imperfect subjunctive can be a very complex mode that even native speakers struggle to use from time to time, so it is not worth get too worked up if you find it difficult. However, we can break the imperfect subjunctive triggers down into five categories. These categories include: past occurrences, current opinions of past events, doubts and wishes, 'if' clauses, and polite suggestions/requests. I am going to explain the first one to you now. When the verb in the independent clause is in the preterite or the imperfect, the subjunctive verb that follows will be imperfect. W E I R D O can be used to remember the verbs that fit this methodology. 'W' stands for Wishes and Desires, 'E' stands for Expressing Emotions, 'I' stands for Impersonal Expressions, 'R' stands for Recommendations and Requests, 'D' stands for Doubt and Denial, and 'O' stands for Ojalá.