sustituir Negative Imperative Conjugation
sustituir — to replace
Negative commands use the present subjunctive forms: no sustituyas, no sustituya.
sustituir Negative Imperative Forms
When to Use the Negative Imperative
Use this to tell someone NOT to replace something, like 'Don't replace the original parts'.
Notes on sustituir in the Negative Imperative
All negative commands for 'sustituir' require the 'y' in the spelling.
Example Sentences
No sustituyas la sal por azúcar.
Don't replace salt with sugar.
tú
No sustituyáis las piezas originales.
Don't (you all) replace the original parts.
vosotros
Common Mistakes
Mistake: Saying 'no sustituye'.
Correct: no sustituyas
Why: Negative commands must use the subjunctive form, not the indicative.
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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.
Preterite
yo: sustituí
In the preterite, sustituir changes 'i' to 'y' in the third-person forms: sustituyó and sustituyeron.
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).