What is the subjunctive and how do I use it?

The subjunctive is a mood meaning it's quite difficult to translate it directly and/or visibly into English. Generally, it follows set phrases. We can group the phrases by their meanings in order to try and remember which of them are followed by subjunctive; WEIRDO (Wishes, Emotions, Impersonal Expressions, Recommendations, Doubt/Denial, Ojalá) is one possible acronym. Use phrases like 'es posible que' or 'quiero que', phrases that express doubt or a wish, and you will be using the subjunctive!