Present Subjuctive

1. When to Use?
   - to describe emotion and uncertainty.

2. How to Form?
 step 1) Start with the yo form of the present indicative. 
 step 2) Drop the -o ending.
 step 3) Add the following endings:
                
   -AR verbs:                             -ER/IR verbs:
     -e          -emos                         -a             -amos
     -es                                           -as
     -e          -en                              -a             -an


 ex. Dudo que usted vaya al Perú en diciembre.
                     -    I doubt that you are going to Peru in December.

3. Trigger words that Subjunctive is NOT used
   
    : creer que ...                    to believe that ...
      no dudar que ...               to not doubt that ...
      es cierto que ...               it is certain that ...
      es claro que ...                 it is clear that ...
      es evidente que ...           it is certain that ...
      es obvio que ...                it is obvious that ...
      estar seguro que ...           to be sure that ...
      es verdad que ...              it is true that ...
      no cabe duda que ...         there's no doubt that ...
      no es dudoso que ...          it is not doubtful that ...
      no hay duda que ...           there is no doubt that ...