Fully irregular verbs — Spanish Verbs List & Guide

The pattern rule

Fully irregular verbs don't follow any single predictable pattern. Their irregularities span multiple tenses and can't be reduced to a simple spelling or stem rule. However, because they are extremely common, most learners acquire their forms through repeated exposure.

💡 Tip Don't try to learn these verbs by rule — learn them by exposure. Because ser, ir, haber, and dar appear constantly in everyday Spanish, you will encounter them thousands of times, and their forms will become automatic.

Example: ser (to be (essential/permanent)) — Present

Irregular forms are highlighted in red. Regular forms for comparison are shown in grey where they differ.

Pronoun	Actual form	Regular would be
yo	soy*	so
tú	eres*	ses
él/ella	es*	se
nosotros	somos*	semos
vosotros	sois*	séis
ellos/ellas	son*	sen

See full conjugation of ser →

Frequently asked questions

Which Spanish verbs are completely irregular?

The most irregular Spanish verbs are ser (to be — permanent), ir (to go), haber (auxiliary "to have"), dar (to give), and saber (to know). These verbs deviate from standard patterns across many tenses and must be memorised individually.

Are ser and ir conjugated the same way?

Interestingly, ser and ir share identical preterite forms: fui, fuiste, fue, fuimos, fuisteis, fueron. Context clarifies which verb is meant. In the imperfect, however, they differ completely: ser → era; ir → iba.

What is the best way to learn fully irregular verbs?

The most effective approach is repeated practice in context. Because fully irregular verbs are the most common in Spanish, consistent reading, listening, and speaking will naturally build familiarity. Spaced repetition drills targeted at their specific forms also help.