When do I need to use the subjunctive?

There are several types of phrases which can trigger the subjunctive. These are easy to remember with the acronym WEIRDO. W - wishes, when you want something to happen (Espero/ deseo que). E - emotion to convey a feeling (estoy contento que). I- impersonal, used for impersonal phrases (es importante que). R - requests/ recommendations (quiero/ recomiendo que). D - doubts (no estoy seguro de que/ dudo que). And finally the word ojalá, meaning I wish that: ojalá que vengas.