Italian Subjunctive Tense

The first use of the subjunctive is after expressions that influence people to carry out an action. Some of the expressions that use the subjunctive in this way are...

Ordinare che- to order
Aspettarsi che- to expect
Permettere che- to allow/permit
Piacere che- to like
Augurarsi che- to wish/hope
Preferire che- to prefer
Comandare che- to order
Proibire che- to prohibit/forbid
Desiderare che- to want
Sperare che- to hope
Impedire che- to prevent
Suggire che- to suggest
Lasciare che- to let/allow
Volere che- to want

eg. Spero che tu possa resistere alla tentazione di provare le droghe leggere .
      I hope that you can resist the temptation to try soft drugs

The same rule covers phrases that indicate necessity and importance...

basta che- it's enough
bisogna che- it is necessary
importa che- it is important
E' essenziale che- it is essential
E' importante che- it is important
E' meglio che- it is better
E necessario che- it is necessary
Occorre che- it is necessary
Pare che- it seems
E' un peccaro che- it's a pity 
Sembra che- it seems
E' urgente che- it's urgent

eg. E' essenziale che gli idoli di molti giovani diano il buon esempio
      It is essential that many young people's idols set a good example.  

The subjunctive is also used after verbs that convey emotion...

avere paura che- to be afraid that
dispiacere che- to regret
essere arrabbiato che- to be annoyed
essere contento che- to be happy
essere deluso che- to be disappointed
essere scandalizzato che- to be outraged
essere sconvolto che- to be upset
essere sorpreso che- to be surprised
essere spiacente che- to be sorry
essere triste che- to be sad
meravigliarsi che- to be amazed 
rincrescere che- to regret
stuprisi che- to be surprised
temere che- to be afraid

eg. Siamo contenti che molte citta abbiano preso dei provvedimenti per combattere l'inquinamento ambientale
      We are happy that lots of cities have taken steps to combat environmental pollution.  

The same rule can be applied to phrases that betray mental reaction...

accettare che- accept that
Piacere che- like that
E' assurdo che- It's absurd that
E' giusto che - it's right that
E' incredibile che- it's incredible that
E' indegno che- it's unworthy that
E' ingiusto che- it's unfair that
E' un peccato che- it's a pity that
E' ridicolo che- it's ridiculous that
E' uno scandalo che- it's a scandal that
E' scandaloso che- it's scandolous that
E' una vergogna che- it's a disgrace that
E' vergognoso che- It's shameful that
non mi importa che- I don't mind that

Eg. E' ridicolo che si debba respirare questa aria velenosa!
      It's ridiculous that one must breath this poisonous air!  

The subjunctive is also used after phrases that demonstrate uncertainty, belief and possibility...

Dire che- to say that
Dubitare che- to doubt that
Essere incerto che- to be uncertain that
Non essere sicure che- to not be sure that
Pensare che- to think that
Credere che- to believe that
Ritenere che- to think that
E' impossibile che- it's impossible that
E' poco probabile che- It's unlikely that
E' possibile che- It's possible that
E' probabile che- It's possible that
Puo darsi che- It may be that

eg.  Puo darsi non sappiano parlare la lingua.
       Maybe they can't speak the language

eg.  Penso che sia un buon'idea
       I think it's a good idea 

Finally, subjunctive moods are often used after conjunctions...

In modo che- in order that
In maniera che- so that
A patto che- provided that
A condizione che- on condition that
A meno che- unles
prima che- before
finche non- until
appena- as soon as 
dopo che- after
ogni volta che- One time that
quando- when
mentre - while
Una volta che- once
sebbene- although
nonostante-despite
malgrado- despite
supponiamo che- Let's suppose that 

eg. Supponiamo che l'aereo parta in orario 
      Let' suppose the plane leaves on time.