From Latin demonstro, demonstrare .
demoustrer
to show ; to demonstrate
This verb conjugates as a first-group verb ending in -er . In the present tense an extra supporting e is needed in the first-person singular indicative and throughout the singular subjunctive, and the third-person singular subjunctive ending -t is lost. Old French conjugation varies significantly by date and by region. The following conjugation should be treated as a guide.
simple
compound
infinitive
demoustrer
avoir demoustré
gerund
en demoustrant
gerund of avoir + past participle
present participle
demoustrant
past participle
demoustré
person
singular
plural
first
second
third
first
second
third
indicative
jo
tu
il
nos
vos
il
simple tenses
present
demoustre
demoustres
demoustre
demoustrons
demoustrez
demoustrent
imperfect
demoustroie , demoustreie , demoustroe , demoustreve
demoustroies , demoustreies , demoustroes , demoustreves
demoustroit , demoustreit , demoustrot , demoustreve
demoustriiens , demoustriens
demoustriiez , demoustriez
demoustroient , demoustreient , demoustroent , demoustrevent
preterite
demoustrai
demoustras
demoustra
demoustrames
demoustrastes
demoustrerent
future
demoustrerai
demoustreras
demoustrera
demoustrerons
demoustreroiz , demoustrereiz , demoustrerez
demoustreront
conditional
demoustreroie , demoustrereie
demoustreroies , demoustrereies
demoustreroit , demoustrereit
demoustreriiens , demoustreriens
demoustreriiez , demoustreriez
demoustreroient , demoustrereient
compound tenses
present perfect
present tense of avoir + past participle
pluperfect
imperfect tense of avoir + past participle
past anterior
preterite tense of avoir + past participle
future perfect
future tense of avoir + past participle
conditional perfect
conditional tense of avoir + past participle
subjunctive
que jo
que tu
qu’il
que nos
que vos
qu’il
simple tenses
present
demoustre
demoustres
demoustre
demoustrons
demoustrez
demoustrent
imperfect
demoustrasse
demoustrasses
demoustrast
demoustrissons , demoustrissiens
demoustrissoiz , demoustrissez , demoustrissiez
demoustrassent
compound tenses
past
present subjunctive of avoir + past participle
pluperfect
imperfect subjunctive of avoir + past participle
imperative
–
tu
–
nos
vos
–
—
demoustre
—
demoustrons
demoustrez
—