Hi Eain,
The subjunctive mood is the verb form used to explore a hypothetical situation or to express a wish, a demand, or a suggestion. Note the verb form changes when a subjunctive is used.
For example, these sentences all use subjunctives:
If I were you, I would eat less sweets.
I wish it were real.
I propose he work full time.
I ask that you be truthful.
If I were free, I'd go.