sustituir Preterite Conjugation
sustituir — to replace
In the preterite, sustituir changes 'i' to 'y' in the third-person forms: sustituyó and sustituyeron.
sustituir Preterite Forms
When to Use the Preterite
Use this for completed replacements that happened at a specific time, such as when a player was substituted in a match or a part was fixed yesterday.
Notes on sustituir in the Preterite
The verb follows the 'i to y' spelling rule in the third person (singular and plural) because the 'i' would otherwise be trapped between two vowels.
Example Sentences
Sustituí la batería del coche ayer.
I replaced the car battery yesterday.
yo
El entrenador sustituyó al delantero en el minuto 80.
The coach substituted the forward in the 80th minute.
él/ella/usted
Sustituimos los muebles viejos el mes pasado.
We replaced the old furniture last month.
nosotros
Common Mistakes
Mistake: Writing 'sustituió' instead of 'sustituyó'.
Correct: sustituyó
Why: In Spanish, an unstressed 'i' between two vowels must change to a 'y'.
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Related Tenses
Present
yo: sustituyo
Sustituir is irregular in the present tense, adding a 'y' before the ending in most forms: sustituyo, sustituyes, sustituye, sustituyen.
Imperfect
yo: sustituía
Sustituir is regular in the imperfect: sustituía, sustituías, sustituía, sustituíamos, sustituíais, sustituían.
Future
yo: sustituiré
The future of sustituir is regular: just add endings to the infinitive (sustituiré, sustituirás).
Conditional
yo: sustituiría
The conditional is regular: add -ía endings to the infinitive 'sustituir'.
Present Subjunctive
yo: sustituya
The present subjunctive follows the 'yo' form of the present indicative, adding a 'y': sustituya, sustituyas, etc.
Imperfect Subjunctive
yo: sustituyera
The imperfect subjunctive is built from the 'sustituyeron' stem: sustituyera, sustituyeras, etc.
Affirmative Imperative
yo: sustituye
Give commands to replace things: sustituye (tú), sustituya (usted), sustituyamos (nosotros).
Negative Imperative
yo: no sustituyas
Negative commands use the present subjunctive forms: no sustituyas, no sustituya.