La o changes to ue in all the singular persons and in the third person of the plural of the present indicative and in the whole present subjunctive.
- O AR acordar, almorzar, apostar *1 , aprobar, asolar *2 , avergonzar, colar, colgar, comprobar, concordar, consolar, contar, costar, degollar, demostrar, desaprobar, descolgar, descontar, desosar *3 , desollar, despoblarse, encontrar, engrosar, esforzarse, forzar, mostrar, poblar, probar, recordar, recostar, reforzar, renovar, repoblar, reprobar, resollar, resonar, revolcar, rodar, rogar, sobrevolar, soldar, soltar, sonar, soñar, tostar, trastocarse, tronar, volar, volcar.
- O ER absolver, cocer, conmover, demoler, desenvolver, devolver, disolver, doler, envolver, escocer, llover, moler, morder, mover, oler *3 , promover, remorder, remover, resolver, retorcer, revolver, soler *4 , torcer, volver *5 .
| Present indicative | Present subjunctive | Imperative |
| Yo cuento | Yo cuente | |
| Tú cuentas | Tú cuentes | Tú cuenta |
| Él cuenta | Él cuente | Usted cuente |
| Nosotros contamos | Nosotros contemos | Nosotros contemos |
| Vosotros contáis | Vosotros contéis | Vosotros contad |
| Ellos cuentan | Ellos cuenten | Ustedes cuenten |
*1 Apostar meaning hacer apuestas is irregular; meaning situar is regular.
*2 Asolar meaning destruir is irregular.
*3 In addition desosar and oler bear h before the diphthong ue: deshueso, huelo, etc.
*4 Soler is defective. It is used in present indicative, present subjunctive and imperfect indicative.
*5 Volver, desenvolver, devolver, envolver and revolver have irregular past participle: vuelto, desenvuelto, devuelto, envuelto, revuelto, etc.