1 The conjugation of a verb is the set of all its forms. Each conjugation includes three non-personal tenses (the infinitive, the gerund and the participle) and four moods (indicative, subjunctive, conditional and imperative).
- Simple tenses of the indicative mood: present, imperfect, preterit, future.
- Perfect tenses of the indicative mood: preterit perfect, pluperfect, preterit anterior, future perfect.
- Simple tenses of the subjunctive mood: present, imperfect, future.
- Perfect tenses of the subjunctive mood: preterit perfect, pluperfect, future perfect.
2 The Spanish verbs are divided in three conjugations: the verbs ending in -ar or first conjugation, the verbs ending in -er or second conjugation, and the verbs ending in -ir or third conjugation. The first conjugation (the verbs ending in -ar) is the most widespread. The newly-created verbs are usually built with the first conjugation.
On the other hand, many verbs in Spanish are irregular. This is one of the most difficult issues for foreign students of Spanish.
See Irregular verbs