Irregular Gerunds

Most gerunds follow the regular pattern of -ando and -iendo. A handful of verbs, however, change their stem or spelling when building the gerund. These irregular forms fall into three tidy groups.

Group 1: Stem Changes in -ir Verbs

Only -ir verbs with a stem change in the present or preterite show a stem change in the gerund. The vowel e becomes i, and o becomes u. -ar and -er verbs never do this.

InfinitiveChangeGerund
dormiro → udurmiendo
moriro → umuriendo
pedire → ipidiendo
servire → isirviendo
venire → iviniendo
decire → idiciendo
repetire → irepitiendo
sentire → isintiendo
preferire → iprefiriendo

El bebé está durmiendo en su cuna.

The baby is sleeping in his crib.

Estoy pidiendo un café con leche.

I am ordering a coffee with milk.

¿Qué está diciendo el profesor?

What is the teacher saying?

Group 2: Vowel + -iendo Becomes -yendo

When the stem of an -er or -ir verb ends in a vowel, the i of -iendo would be trapped between two vowels. Spanish avoids that cluster by turning the i into a y.

InfinitiveStemGerund
leerle-leyendo
creercre-creyendo
oíro-oyendo
caerca-cayendo
traertra-trayendo
huirhu-huyendo
construirconstru-construyendo
incluirinclu-incluyendo

Estamos leyendo un libro muy interesante.

We are reading a very interesting book.

Los niños están cayendo de risa.

The children are falling over laughing.

Están construyendo un puente nuevo.

They are building a new bridge.

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This same i → y change appears in the preterite third-person forms (leyó, oyeron). See Other Spelling Changes for the parallel pattern.

Group 3: Two Special Cases

Two very common verbs have gerunds you simply memorize.

  • iryendo — the verb ir has no usable stem to attach -iendo to, so Spanish uses yendo. It is rare in the progressive but appears in other constructions.
  • poderpudiendopoder shows an o → u change even though it is an -er verb.

Voy yendo al mercado poco a poco.

I am slowly heading to the market.

No pudiendo esperar más, se fue.

Unable to wait any longer, he left.

Putting It Together

Once you have the right gerund, the structure is the same as for regular verbs: estar + gerund. The gerund never changes for gender or number.

Subjectdormir (o → u)leer (vowel + y)
yoestoy durmiendoestoy leyendo
estás durmiendoestás leyendo
él / ella / ustedestá durmiendoestá leyendo
nosotros / nosotrasestamos durmiendoestamos leyendo
ellos / ellas / ustedesestán durmiendoestán leyendo
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A useful shortcut: if an -ir verb changes its stem in the third-person preterite (pidió, durmió), it will show the same change in the gerund (pidiendo, durmiendo). Learn one and you get the other for free.

For when and when not to use these forms, continue with Usage and Restrictions.

Related Topics

  • Formation (Estar + Gerund)A2Form the present progressive by conjugating estar in the present and adding the invariable gerund.
  • Usage and RestrictionsA2The Spanish progressive is reserved for actions happening right now and avoids near-future meanings and stative verbs.
  • Stem Change: E to IB1Stem-changing -ir verbs with e in the stem shift to i in the third-person preterite forms: pidió, pidieron.