When do I use the subjunctive in Spanish?

The subjunctive is a mood, not a tense. The other ‘moods’ would be the indicative and the imperative. The subjunctive also exists in English (“If I were rich, I would…”) but it is much more common in Spanish. It is used when talking about desires, emotions, doubts and the unknown. All of this might seem pretty abstract, but luckily there’s a handy acronym you can memorise to remember all of the situations in which we might need to use the subjunctive mood, W.E.I.R.D.O.
W – wishes and desires (espero que tengas un buen día – I hope you have a good day)E – emotions (me alegro de que te guste – I’m glad you like it)I – impersonal expressions (es importante que leas este libro – it’s important that you read this book)R – recommendations and requests (recomiendo que tomes más agua – I recommend that you drink more water)D – doubt (dudo que tengas mi dirección – I doubt that you have my address)O – ojalá. This is a bit of an odd one out, but you must always use the subjunctive when using ojalá, which means I hope / I pray / If only (ojalá que él recuerde – I hope that he remembers).
This is a simple way of remembering most of the situations in which we need to use the subjunctive. Especially when writing essays in Spanish, ask yourself every time you use a verb if is complies with one of the W.E.I.R.D.O situations. If so, you need a subjunctive. Using subjunctives can be a good way to boost marks for grammar and sophistication in A level exams.