Spanish grammar · interactive
Stem-Changing Verbs Practice
Quiero, puedo, pido — the vowel shifts, but only inside the “boot.” Drill e→ie, o→ue and e→i with instant feedback.
These exercises target the stem changing verbs Spanish textbooks call “boot verbs”: querer → quiero, poder → puedo, pedir → pido. You’ll pick the right form in real sentences and see exactly which pattern applied — and, just as important, when the stem doesn’t change at all.
The short version: in the present tense the stressed stem vowel changes (e→ie, o→ue, or e→i) in every form except nosotros and vosotros — draw a line around the changing forms in a conjugation chart and you get a boot shape.
Try the stem-changing verbs exercise
Choose the correctly conjugated form. You’ll see the pattern after each answer.
Yo ir al cine esta noche.
I want to go to the movies tonight.
How it works
- 1
Read the sentence
A real Spanish sentence appears with the verb blanked out.
- 2
Pick the right form
Changed stem or plain stem? Instant right/wrong feedback.
- 3
Learn the why
Every answer names the pattern (e→ie, o→ue, e→i) and whether the form is inside the boot.
What you’ll learn
- The three core patterns: e→ie (querer), o→ue (poder), e→i (pedir)
- Why nosotros and vosotros never change — the “boot” shape and stress
- High-frequency stem-changers: querer, poder, pensar, dormir, pedir, empezar, volver
- The odd one out: jugar and its unique u→ue change
It’s about stress, not memorization
Stem-changing verbs look like a long list to memorize, but there’s one mechanism underneath: when the stem vowel carries the stress, it changes; when the ending carries the stress, it doesn’t. In quiero the stress hits the stem (QUIE-ro), so e becomes ie. In queremos the stress hits the ending (que-RE-mos), so the e survives untouched. That’s the entire reason nosotros and vosotros are exempt — their endings steal the stress.
Draw a present-tense chart and circle the forms that change — yo, tú, él/ella, ellos/ellas — and you get the famous boot (or shoe) shape. The boot isn’t a trick; it’s a picture of where the stress falls. Once you hear the stress, you can predict the change in verbs you’ve never conjugated before.
Traps: e→i, jugar, and knowing which verbs change at all
The e→i pattern is the sneaky one. It only appears in -ir verbs (pedir → pido, servir → sirve, repetir → repite), and learners often wrongly apply e→ie to them (‘piedo’ doesn’t exist). If it’s an -ar or -er verb with a stem change, the e can only go to ie — pensar → pienso, entender → entiendo. Only -ir verbs get to choose between ie (preferir → prefiero) and i (pedir → pido), and each verb’s choice is fixed.
Two more things to keep straight. Jugar stands alone as the only u→ue verb: juego, juegas, but jugamos. And not every verb with an e or o in the stem changes — comer is just como, never ‘cuemo’. Dictionaries mark the pattern next to the infinitive, like ‘pedir (e:i)’, and drilling in sentences builds the instinct for which verbs shift and which don’t.
Quick reference: the stem-change patterns
| Pattern | Example verb |
|---|---|
| e → ie | querer → quiero (also pensar, empezar, entender) |
| o → ue | poder → puedo (also dormir, volver, costar) |
| e → i (-ir verbs only) | pedir → pido (also servir, repetir) |
| u → ue (one verb) | jugar → juego |
| No change: nosotros / vosotros | queremos, podéis, pedimos — stress is on the ending |
Frequently asked questions
What are stem-changing verbs in Spanish?
Verbs whose stem vowel changes in the present tense when it’s stressed: querer → quiero (e→ie), poder → puedo (o→ue), pedir → pido (e→i). The endings stay completely regular — only the vowel in the stem shifts.
Why don’t nosotros and vosotros change?
Because in those forms the stress falls on the ending, not the stem (que-RE-mos), and the vowel only changes when it’s stressed. That’s why the changing forms trace a boot shape on a conjugation chart.
What are the three types of stem changes?
E→ie (querer, pensar, empezar), o→ue (poder, dormir, volver), and e→i (pedir, servir, repetir). The e→i type occurs only in -ir verbs. Jugar adds a fourth, one-verb pattern: u→ue.
How do I know if a verb is stem-changing?
You can’t tell from the infinitive alone — querer changes but comer doesn’t. Dictionaries flag it, e.g. ‘dormir (o:ue)’, and with practice the high-frequency stem-changers become automatic because you’ve seen quiero and puedo thousands of times.
Make the boot automatic
Charts show you the pattern; production makes it stick. HablaCore drills stem-changing verbs in real AI-generated sentences with instant feedback, so quiero vs queremos stops needing thought.
Practice stem-changing verbs in real sentences