when should I use the subjunctive in Italian?

The subjunctive is used far more in Italian than it is used in many languages and consequently it is very important to understand when. The most common use is following an opinion phrase such as penso che (I think that) Unlike in Spanish the subjunctive is used following both positive and negative opinion. Another very common use is that it is used following verbs that express wanting or volition like amare che (to love that) or Sperare che (to hope that). further to this verbs that express doubt also take the subjunctive such as dubitare (To doubt) The subjunctive should also be used when the verb 'essere' is used in an impersonal form. For example è necessario che (it is necessary that) requires the subjunctive. Finally it should also be used following certain set phrases and triggers that can be used to enhance the quality of a piece of written work.