To form the present subjunctive of a regular verb, take the first person indicative form of the verb and, with -ar verbs, change the -o ending to -e. The table below shows the endings for regular -ar verbs.

As an example, the first person indicative form of the verb hablar (to speak) is hablo. The table below shows the conjugation of hablar:

Let's look at some example sentences using the present subjunctive. The first sentences use the verb hablar (to speak) while the next sentence uses the verb firmar (to sign).

Es preciso que le hables.
It's necessary that you talk to him.

Necesitamos que usted hable con el investigador de incendios.
We need you to talk to the fire investigator.

Necesito que usted firme esto.
I need you to sign this.