When do I use the subjunctive?

There are many times in Spanish when you are required to use the subjunctive, but for now I will explain in detail one common category of uses that tend to cause confusion for Spanish students. This can be labelled as 'Influence, Emotion, Judgement' (IEJ)INFLUENCE involves verbs that influence others, causing them to do a certain action. For example after verbs of wanting, ordering, requiring, suggesting etc. + quee.g. quiero que pasar la aspiradora ahora mismo - I want you to hoover right now' NB: the subjects of the two verbs usually MUST BE DIFFERENT for it to be subjunctive however there also are exceptions with some verbs like causar and hacer where you can use an infinitive (e.g. nos hizo salir- he made us leave)EMOTION involves emotional reactions after verbs/ expressions of joy, sadness, anger, sorrow, bother, frustration, surprise, and other emotions, hope and fear (espero/ temo: also uncertainty) + quee.g 'me alegro que te pasaras bien- I'm happy that you had a good time' or 'estoy harto de que no me respondas- I'm fed up of you not answering me'JUDGEMENTS are like emotion statements but less personal and more observational: they tend to include reactions/ expressions of indignation, justification, approval, disapproval, concern, worth (i.e. importance, neccesity) etc. + quee.g. es importante que tomes cuidado - it's important that you be careful' or Cómo puedes justificar que se comparten así?- How can you justify them behaving like this?'Other uses include doubt, uncertainty, possibility, purpose and other miscellaneous uses which can be explained in more detail.