Stem-Changing Verbs (Junior Cert Spanish): Revision Notes
Stem-changing verbs
Overview
Stem-changing verbs are a special group of Spanish verbs that behave differently in the present tense. While their endings follow the normal patterns you already know, something interesting happens to the main part of the verb (called the stem). In certain forms, one vowel in the stem transforms into something else entirely.
These verbs are sometimes called "boot verbs" because if you draw a line around the forms that change, it looks like a boot shape on the conjugation table. The changes only happen when the stem is stressed, which means nosotros and vosotros always keep their original stems.
The "boot" pattern gets its name because when you highlight all the forms that undergo stem changes on a conjugation table (yo, tú, usted, él/ella, ustedes, ellos/ellas), the shape resembles a boot. The two forms that don't change (nosotros and vosotros) sit outside this "boot" pattern.
Rules & formation
The formation process is straightforward once you understand the pattern. Take any stem-changing verb and conjugate it like a regular verb, but apply the vowel change to all forms except nosotros and vosotros.
There are three main types of stem changes in the present tense:
- e → ie (the 'e' becomes 'ie')
- o → ue (the 'o' becomes 'ue')
- u → ue (the 'u' becomes 'ue' - only with jugar)
Key Rule: The stem changes only occur when the stem is stressed. This means nosotros and vosotros forms never change their stems - they always keep the original vowel from the infinitive.
Tables of key forms
e → ie verbs
Querer (to want, to like)
| Pronoun | Spanish | English |
|---|---|---|
| yo | quiero | I want |
| tú | quieres | You want (informal) |
| usted | quiere | You want (formal) |
| él/ella | quiere | He/she wants |
| nosotros/as | queremos | We want |
| vosotros/as | queréis | You want (informal, plural) |
| ustedes | quieren | You want (formal, plural) |
| ellos/ellas | quieren | They want |
Preferir (to prefer)
| Pronoun | Spanish | English |
|---|---|---|
| yo | prefiero | I prefer |
| tú | prefieres | You prefer (informal) |
| usted | prefiere | You prefer (formal) |
| él/ella | prefiere | He/she prefers |
| nosotros/as | preferimos | We prefer |
| vosotros/as | preferís | You prefer (informal, plural) |
| ustedes | prefieren | You prefer (formal, plural) |
| ellos/ellas | prefieren | They prefer |
Empezar (to begin)
| Pronoun | Spanish | English |
|---|---|---|
| yo | empiezo | I begin |
| tú | empiezas | You begin (informal) |
| usted | empieza | You begin (formal) |
| él/ella | empieza | He/she begins |
| nosotros/as | empezamos | We begin |
| vosotros/as | empezáis | You begin (informal, plural) |
| ustedes | empiezan | You begin (formal, plural) |
| ellos/ellas | empiezan | They begin |
o → ue verbs
Poder (to be able to, can)
| Pronoun | Spanish | English |
|---|---|---|
| yo | puedo | I can |
| tú | puedes | You can (informal) |
| usted | puede | You can (formal) |
| él/ella | puede | He/she can |
| nosotros/as | podemos | We can |
| vosotros/as | podéis | You can (informal, plural) |
| ustedes | pueden | You can (formal, plural) |
| ellos/ellas | pueden | They can |
Volver (to return)
| Pronoun | Spanish | English |
|---|---|---|
| yo | vuelvo | I return |
| tú | vuelves | You return (informal) |
| usted | vuelve | You return (formal) |
| él/ella | vuelve | He/she returns |
| nosotros/as | volvemos | We return |
| vosotros/as | volvéis | You return (informal, plural) |
| ustedes | vuelven | You return (formal, plural) |
| ellos/ellas | vuelven | They return |
u → ue verbs
Jugar (to play)
| Pronoun | Spanish | English |
|---|---|---|
| yo | juego | I play |
| tú | juegas | You play (informal) |
| usted | juega | You play (formal) |
| él/ella | juega | He/she plays |
| nosotros/as | jugamos | We play |
| vosotros/as | jugáis | You play (informal, plural) |
| ustedes | juegan | You play (formal, plural) |
| ellos/ellas | juegan | They play |
Example sentences
Worked Examples: Stem-changing verbs in context
Querer examples:
- Yo quiero una pizza. → I want a pizza. (The stem changes from 'quer-' to 'quier-' because it's stressed.)
- Nosotros queremos estudiar. → We want to study. (No stem change in the nosotros form.)
Poder examples:
- ¿Puedes ayudarme? → Can you help me? (The 'o' changes to 'ue' in the tú form.)
- Ellos pueden hablar español. → They can speak Spanish. (The stem change appears in the ellos form too.)
Jugar examples:
- Mi hermano juega al fútbol. → My brother plays football. (Notice 'jugar a' is used for sports.)
- Jugamos en el parque. → We play in the park. (No stem change with nosotros.)
Common mistakes & tips
Forgetting which forms change: Remember the "boot" pattern - only nosotros and vosotros keep the original stem. All other forms undergo the vowel change.
Mixing up jugar and tocar: Use jugar for playing sports or games (jugar al fútbol, jugar al ajedrez), but use tocar for playing musical instruments (tocar la guitarra, tocar el piano).
Study Tip: Practice each type separately. Master e→ie verbs like querer, o→ue verbs like poder, and u→ue with just jugar one pattern at a time.
Forgetting accents: Many of these verbs have accents in certain forms (queréis, podéis, preferís). Don't forget them in your written work.
Mini practice
Practice Exercise
Spanish → English:
- Ella quiere un café.
- Podemos ir al cine.
- ¿Juegas al tenis?
English → Spanish: 4. I prefer tea. 5. We begin at nine o'clock. 6. You (informal) can't come.
Answers:
- She wants a coffee.
- We can go to the cinema.
- Do you play tennis?
- Prefiero té.
- Empezamos a las nueve.
- No puedes venir.
Key Points to Remember:
- Stem-changing verbs only change in the present tense when the stem is stressed
- The changes follow a "boot" pattern - nosotros and vosotros never change
- e→ie verbs include querer, preferir, and empezar
- o→ue verbs include poder and volver
- jugar is the only common u→ue verb, and it's used for sports and games, not instruments