(This etymology is missing or incomplete. Please add to it, or discuss it at the Etymology scriptorium .)
Identical in form to the archaic future perfects in -āssō , -āssere , etc., attested contemporary with Ennius, viz. amāssis , levāssō , impetrāssere , and iūdicāssit , respectively of amō , levō , impetrō , and iūdicō .[ 1] [ 2] Origin cited as not fully explained. Perhaps connected with a kind of prolepsis invoking a counterfactual use of aspect for emphasis.
-essō (present infinitive -essere , perfect active -essīvī or -essiī or -essī , supine -essītum ) ; third conjugation
Forms a small number of intensive verbs from verbs.
petessō ( “ I strive eagerly ” ) , from the verb petō ( “ I aim, seek ” ) .
facessō ( “ I do eagerly; I depart ” ) , from the verb I do, make
Conjugation of -essō (third conjugation )
indicative
singular
plural
first
second
third
first
second
third
active
present
-essō
-essis
-essit
-essimus
-essitis
-essunt
imperfect
-essēbam
-essēbās
-essēbat
-essēbāmus
-essēbātis
-essēbant
future
-essam
-essēs
-esset
-essēmus
-essētis
-essent
perfect
-essīvī , -essiī , -essī
-essīvistī , -essiistī , -essistī
-essīvit , -essiit , -essit
-essīvimus , -essiimus , -essimus
-essīvistis , -essiistis , -essistis
-essīvērunt , -essīvēre , -essiērunt , -essiēre , -essērunt , -essēre
pluperfect
-essīveram , -essieram , -esseram
-essīverās , -essierās , -esserās
-essīverat , -essierat , -esserat
-essīverāmus , -essierāmus , -esserāmus
-essīverātis , -essierātis , -esserātis
-essīverant , -essierant , -esserant
future perfect
-essīverō , -essierō , -esserō
-essīveris , -essieris , -esseris
-essīverit , -essierit , -esserit
-essīverimus , -essierimus , -esserimus
-essīveritis , -essieritis , -esseritis
-essīverint , -essierint , -esserint
sigmatic future1
-ō
-is
-it
-imus
-itis
-int
passive
present
-essor
-esseris , -essere
-essitur
-essimur
-essiminī
-essuntur
imperfect
-essēbar
-essēbāris , -essēbāre
-essēbātur
-essēbāmur
-essēbāminī
-essēbantur
future
-essar
-essēris , -essēre
-essētur
-essēmur
-essēminī
-essentur
perfect
-essītus + present active indicative of sum
pluperfect
-essītus + imperfect active indicative of sum
future perfect
-essītus + future active indicative of sum
sigmatic future1
-or
-eris
-itur
—
—
—
subjunctive
singular
plural
first
second
third
first
second
third
active
present
-essam
-essās
-essat
-essāmus
-essātis
-essant
imperfect
-esserem
-esserēs
-esseret
-esserēmus
-esserētis
-esserent
perfect
-essīverim , -essierim , -esserim
-essīverīs , -essierīs , -esserīs
-essīverit , -essierit , -esserit
-essīverīmus , -essierīmus , -esserīmus
-essīverītis , -essierītis , -esserītis
-essīverint , -essierint , -esserint
pluperfect
-essīvissem , -essiissem , -essissem
-essīvissēs , -essiissēs , -essissēs
-essīvisset , -essiisset , -essisset
-essīvissēmus , -essiissēmus , -essissēmus
-essīvissētis , -essiissētis , -essissētis
-essīvissent , -essiissent , -essissent
sigmatic aorist1
-im
-īs
-īt
-īmus
-ītis
-int
passive
present
-essar
-essāris , -essāre
-essātur
-essāmur
-essāminī
-essantur
imperfect
-esserer
-esserēris , -esserēre
-esserētur
-esserēmur
-esserēminī
-esserentur
perfect
-essītus + present active subjunctive of sum
pluperfect
-essītus + imperfect active subjunctive of sum
imperative
singular
plural
first
second
third
first
second
third
active
present
—
-esse
—
—
-essite
—
future
—
-essitō
-essitō
—
-essitōte
-essuntō
passive
present
—
-essere
—
—
-essiminī
—
future
—
-essitor
-essitor
—
—
-essuntor
non-finite forms
active
passive
present
perfect
future
present
perfect
future
infinitives
-essere
-essīvisse , -essiisse , -essisse
-essītūrum esse
-essī
-essītum esse
-essītum īrī
participles
-essēns
—
-essītūrus
—
-essītus
-essendus , -essundus
verbal nouns
gerund
supine
genitive
dative
accusative
ablative
accusative
ablative
-essendī
-essendō
-essendum
-essendō
-essītum
-essītū
1 At least one use of the archaic "sigmatic future" and "sigmatic aorist" tenses is attested, which are used by Old Latin writers; most notably Plautus and Terence . The sigmatic future is generally ascribed a future or future perfect meaning, while the sigmatic aorist expresses a possible desire ("might want to"). It is also attested as having a rare sigmatic future passive indicative form ("will have been"), which is not attested in the plural for any verb.