Decidere (to decide) is one of the verbs you reach for several times a day in Italian — every time someone decides to do something, makes a decision, makes up their mind. Its present and imperfect are perfectly regular -ere forms. The wrinkles sit, as so often, in the passato remoto (strong 1-3-3 pattern: decisi / decise / decisero) and the past participle (deciso, with the -so ending rather than -duto). The same -so template recurs in chiusi → chiuso, misi → messo, presi → preso, spesi → speso, rasi → raso — once you see the shape, half the strong -ere participles fall into place.
The other thing that makes decidere worth its own page is the construction. Decidere + di + infinitive is one of the workhorse infinitive-with-preposition patterns of Italian; it carries every "I decided to leave / to stay / to write to her" sentence you'll ever produce. There is also a reflexive sibling, decidersi a, with a meaningfully different shade — closer to "to make up one's mind to" — and you should know the difference because the prepositions are not interchangeable.
Indicativo presente
| Person | Form |
|---|---|
| io | decido |
| tu | decidi |
| lui / lei / Lei | decide |
| noi | decidiamo |
| voi | decidete |
| loro | decidono |
Fully regular -ere present. Stress sits on the stem dec- in the singular and 3pl (decìdo, decìdi, decìde, decìdono) and shifts to the ending in noi and voi.
Decidi tu dove andiamo a cena stasera.
You decide where we're going for dinner tonight.
Decidiamo insieme, non ho preferenze.
Let's decide together, I don't have a preference.
Sono i clienti che decidono il successo di un ristorante.
It's the customers who decide a restaurant's success.
Imperfetto
| Person | Form |
|---|---|
| io | decidevo |
| tu | decidevi |
| lui / lei / Lei | decideva |
| noi | decidevamo |
| voi | decidevate |
| loro | decidevano |
The imperfect is the tense for habitual or ongoing past decision-making — who used to decide things, how decisions were made over time, the moment when you were still in the act of deciding.
In casa nostra era sempre la nonna a decidere il menù della domenica.
At our house, it was always Grandma who decided the Sunday menu.
Stavo ancora decidendo quando il cameriere è tornato.
I was still deciding when the waiter came back.
Passato remoto
| Person | Form |
|---|---|
| io | decisi |
| tu | decidesti |
| lui / lei / Lei | decise |
| noi | decidemmo |
| voi | decideste |
| loro | decisero |
The classic 1-3-3 strong pattern: irregular short stem decis- for io, lui/lei, loro; regular decid- for tu, noi, voi. The 1sg ending is -i rather than the regular -ei of weak -ere verbs (credei), and the consonant cluster gets squeezed: decid- → decis-. This is the same compression that gives prendere → presi, chiudere → chiusi, mettere → misi.
Decisi di partire la mattina dopo, senza salutare nessuno.
I decided to leave the next morning, without saying goodbye to anyone.
Quel giorno decidemmo di non rivederci più.
That day we decided we'd never see each other again.
Futuro semplice
| Person | Form |
|---|---|
| io | deciderò |
| tu | deciderai |
| lui / lei / Lei | deciderà |
| noi | decideremo |
| voi | deciderete |
| loro | decideranno |
Built regularly from decider- plus the standard endings. The grave accent on deciderò and deciderà is mandatory.
Deciderò domani — ora sono troppo stanco.
I'll decide tomorrow — I'm too tired now.
Saranno i giudici a decidere chi vince.
The judges will be the ones deciding who wins.
Condizionale presente
| Person | Form |
|---|---|
| io | deciderei |
| tu | decideresti |
| lui / lei / Lei | deciderebbe |
| noi | decideremmo |
| voi | decidereste |
| loro | deciderebbero |
Used for hypothetical decisions ("I would decide…"), polite suggestions, and the consequent of se + imperfect-subjunctive conditionals. As always, watch the orthographic trap: decideremmo (conditional, double m) versus decideremo (future, single m).
Al posto tuo, deciderei io e basta.
If I were you, I'd just decide and be done with it.
Decideremmo volentieri, ma ci servono più informazioni.
We'd happily decide, but we need more information.
Congiuntivo presente
| Person | Form |
|---|---|
| (che) io | decida |
| (che) tu | decida |
| (che) lui / lei | decida |
| (che) noi | decidiamo |
| (che) voi | decidiate |
| (che) loro | decidano |
The three singulars collapse into decida, so subject pronouns or context disambiguate after triggers like bisogna che, è ora che, voglio che.
È ora che tu decida cosa vuoi fare nella vita.
It's time you decided what you want to do with your life.
Aspettiamo che decidano loro, è una loro responsabilità.
Let's wait for them to decide, it's their responsibility.
Congiuntivo imperfetto
| Person | Form |
|---|---|
| (che) io | decidessi |
| (che) tu | decidessi |
| (che) lui / lei | decidesse |
| (che) noi | decidessimo |
| (che) voi | decideste |
| (che) loro | decidessero |
Standard imperfect-subjunctive endings on the regular stem. Used in past-tense subjunctive contexts and as the if-clause of se + imperfect-subjunctive conditionals.
Se decidessimo subito, potremmo prenotare ancora i posti migliori.
If we decided right now, we could still book the best seats.
Speravo che decidessi tu per tutti.
I was hoping you'd decide for everyone.
Imperativo
| Person | Form |
|---|---|
| tu | decidi |
| Lei (formal) | decida |
| noi | decidiamo |
| voi | decidete |
| loro (formal pl.) | decidano |
A useful and frequently used set: decidi tu ("you decide"), decidiamo ("let's decide"), decida pure ("please decide" — formal, slightly inviting). Negative tu, as always, uses the infinitive: non decidere ora.
Deciditi! Andiamo o restiamo?
Make up your mind! Are we going or staying?
Non decidere subito, prenditi un giorno per pensarci.
Don't decide right away, take a day to think it over.
Forme non finite
| Form | Italian |
|---|---|
| Infinito presente | decidere |
| Infinito passato | avere deciso |
| Gerundio presente | decidendo |
| Gerundio passato | avendo deciso |
| Participio passato | deciso |
The participle deciso lines up exactly with the strong passato remoto: decis-i → decis-o. This is the -so branch of the irregular -ere participles, distinct from the -sto branch (chiesto, risposto). Memorising the passato remoto stem buys you the participle for free, since they are essentially the same shape.
Avendo deciso di non sposarsi, hanno comprato due case separate.
Having decided not to get married, they bought two separate houses.
Compound tenses (auxiliary: avere)
Decidere is transitive (or used absolutely), so it always takes avere. The participle stays invariable except when a direct-object pronoun precedes — but with decidere the object is more often di + infinitive than a noun, so the agreement question rarely comes up.
| Tense | io | tu | noi |
|---|---|---|---|
| Passato prossimo | ho deciso | hai deciso | abbiamo deciso |
| Trapassato prossimo | avevo deciso | avevi deciso | avevamo deciso |
| Trapassato remoto | ebbi deciso | avesti deciso | avemmo deciso |
| Futuro anteriore | avrò deciso | avrai deciso | avremo deciso |
| Condizionale passato | avrei deciso | avresti deciso | avremmo deciso |
| Congiuntivo passato | abbia deciso | abbia deciso | abbiamo deciso |
| Congiuntivo trapassato | avessi deciso | avessi deciso | avessimo deciso |
Abbiamo deciso di vendere la casa al mare.
We've decided to sell the beach house.
Se avessi deciso prima, avremmo trovato voli più economici.
If you'd decided earlier, we'd have found cheaper flights.
The construction: decidere di + infinitive
This is the construction that handles roughly nine out of ten uses of decidere. Decidere + di + the bare infinitive of what you've decided to do.
Ho deciso di studiare medicina.
I've decided to study medicine.
Hanno deciso di non andare in vacanza quest'anno.
They've decided not to go on holiday this year.
Decidi di smettere o vai avanti?
Are you deciding to stop or to keep going?
You can also decide something (a noun): decidere il vincitore, decidere il prezzo, decidere la data. And you can decide on something with decidere su: abbiamo deciso sulla data, ora ci manca il luogo ("we've settled on the date, now we just need the venue").
I giudici hanno deciso il vincitore all'unanimità.
The judges decided the winner unanimously.
Dobbiamo ancora decidere sul colore delle pareti.
We still have to decide on the colour of the walls.
Decidersi a + infinitive (reflexive)
The reflexive decidersi carries a stronger nuance: not just to decide but to make up one's mind after some hesitation, foot-dragging or back-and-forth. The preposition is a, not di — this is the trap. Decidersi *a + infinito*.
Finalmente si è deciso a chiamare il dottore.
He finally made up his mind to call the doctor.
Mi sono deciso a comprare la macchina nuova.
I've made up my mind to buy the new car.
Decidetevi! Non possiamo aspettare tutto il giorno.
Make up your minds! We can't wait all day.
The semantic difference is real. Ho deciso di partire presents the decision as a clean act. Mi sono deciso a partire presents it as the conclusion of a process — there was hesitation, now it's resolved. Use decidersi a when you want to communicate the finally in I've finally decided.
Common mistakes
❌ Ho deciduto di restare.
Incorrect — the participle is irregular.
✅ Ho deciso di restare.
Correct — deciso is the irregular -so participle.
❌ Ho deciso a partire domani.
Incorrect — non-reflexive decidere takes 'di', not 'a'.
✅ Ho deciso di partire domani.
Correct — decidere di + infinitive.
❌ Mi sono deciso di chiamarla.
Incorrect — the reflexive decidersi takes 'a', not 'di'.
✅ Mi sono deciso a chiamarla.
Correct — decidersi a + infinitive.
❌ Penso che decide bene.
Incorrect — penso che triggers the subjunctive.
✅ Penso che decida bene.
Correct — decida is the congiuntivo presente.
❌ Ieri decidevo di smettere di fumare.
Wrong tense — a single, completed decision is not imperfect.
✅ Ieri ho deciso di smettere di fumare.
Correct — a one-time, perfective decision takes the passato prossimo.
Key takeaways
Two prepositions, two meanings: decidere *di
- infinito = "to decide to (do)"; decidersi **a
- infinito = "to make up one's mind to (do)". The reflexive carries the nuance of *finally.
- infinito = "to decide to (do)"; decidersi **a
Strong -so participle: the past participle is deciso, lining up with the passato remoto decisi / decise / decisero. Same template as chiuso, preso, messo, speso.
Always avere as auxiliary: even though English speakers sometimes feel the verb is "about" the deciding self (especially in the reflexive), in Italian only the reflexive decidersi takes essere — and there it's the reflexive marker that triggers it, not the verb itself.
The natural drilling neighbours are chiudere (same -so participle template) and chiedere / rispondere (same strong-passato-remoto rhythm).
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Open the Italian course →Related Topics
- Chiedere: Full ConjugationA2 — Complete paradigm of chiedere (to ask for, request) — a high-frequency -ere verb with the classic -si / -sto irregular passato remoto and participle.
- Rispondere: Full ConjugationA2 — Complete paradigm of rispondere (to answer, to reply) — the natural mirror of chiedere, with the same strong -si / -sto irregular pattern.
- Chiudere: Full ConjugationA2 — Complete paradigm of chiudere (to close, to shut) — a strong -ere verb with the -si passato remoto, irregular -so participle chiuso, and a wide spread of figurative uses.
- Presente: Regular -ere VerbsA1 — How to conjugate the second-conjugation -ere verbs in the present indicative — the smallest of the three classes, but home to many of the most common verbs in the language.