The basic use of the subjunctive mood El uso básico del subjuntivo 
The subjunctive is not a tense; rather, it is a mood. The subjunctive mood is widely used in Spanish.
Tense refers to when an action takes place (past, present, future,...)
while mood reflects how the speaker feels about the action. 
Indicates action, process, or identity as dependent on the speaker's reaction to it.
Los modos mas comunes del SUBJUNTIVO son:
The subjunctive more common tenses are:
persona (person) 
Presente:                            yo (I) coma
Imperfecto:                        yo  comiera
Presente perfecto:              yo  haya  comido
Pluscuamperfecto:              yo  hubiera/ hubiese  comido
when to use the subjunctive.?
The subjunctive is used to reflect the speaker's feelings or attitudes toward events,  when the feelings or attitudes are: 
 uncertain, unreal, or hypothetical.
Expressions of volitions, doubt, surprise, fear, represent reactions to the speaker's perception of reality,
 they are naturally expressed in Spanish by the subjunctive.
The Spanish subjunctive is used in subordinate, or dependent, clauses.
(main clause) (dependent clause) (main clause) (dependent clause)
Sugiero  que vuelva mañana. I suggest  that you come back tomorrow.
The expression that requires the use of the subjunctive is in the main clause (sugiero)
The subjunctive appears in the dependent clause ( que vuelva mañana)
The subjunctive mood is used because the action of  "vuelva", "come back"  is not real; it is only a suggestion.

page 1 of 12