Irregular IR Verbs 2
Spanish: Edexcel IGCSE, topic 8.1.10
Stem Changing Verbs (O → UE)
When conjugated in the present tense, some -IR verbs change. The 'u' in the infinitive becomes 'ue'. This does NOT happen in the 'nosotros' and 'vosotros' forms. Derivatives of these verbs follow the same pattern.

Stem changes O → UE
- When conjugated, these IR verbs change from their infinitive form.
- The 'o' in the infinitive changes to 'ue' when conjugated.
- E.g. Morir (to die) becomes 'muero' (I die).
- E.g. Muero, mueres, muere, morimos, morís, mueren.

Dormir - to sleep
- Duermo - I sleep.
- Duermes - you sleep.
- Duerme - he/she sleeps / you sleep (formal).
- Dormimos - we sleep.
- Dormís - you sleep (plural).
- Duermen - they sleep / you sleep (formal plural).

Morir - to die
- Muero - I die.
- Mueres - you die.
- Muere - he/she dies / you die (formal).
- Morimos - we die.
- Morís - you die (plural).
- Mueren - they die / you die (formal plural).
Verbs That End in UIR
Verbs that end in UIR in the present tense drop IR and add a 'y' and the normal endings. This does NOT happen in the 'nosotros' and 'vosotros form'. Derivatives of these verbs follow the same pattern.

Construir - to build
- Construyo - I build.
- Construyes - you build.
- Construye - he/she builds / you build (formal).
- Construimos - we build.
- Construís - you build (plural).
- Construyen - they build / you build (formal plural).

Contribuir - to contribute
- Contribuyo - I contribute.
- Contribuyes - you contribute.
- Contribuye - he/she contributes / you contribute (formal).
- Contribuimos - we contribute.
- Contribuís - you contibute (plural).
- Contribuyen - they contribute / you contribute (formal plural).
Test yourself on Irregular IR Verbs 2
¿Qué significa 'dormimos' en Inglés?
How do you say 'they build' in Spanish?