Verbs Grammar Index Page

The Family of sum

Common forms of sum

sum, esse, fuî, futurus 'to be'
possum, posse, potuî, ---- 'to be able, can'
adsum, adesse, adfuî, ---- 'to be near' (preposition ad + sum)
absum, abesse, afuî, ---- 'to be away' 'to be absent' (preposition ab + sum)
desum, deesse, defui, ---- 'to be lacking, wanting'

Notes on verb morphology

Present indicative tense

sum possum adsum absum desum
es potes ades abes dees
est potest adest abest deest
sumus possumus adsumus absumus desumus
estis potestis adestis abestis deestis
sunt possunt adsunt absunt desunt

Imperfect indicative tense

The imperfect tense is the root (ab, ad, de,pot) + the imperfect endings of esse:

eram poteram aderam aberam deeram
eras poteras aderas aberas deeras
erat poterat aderat aberat deerat
eramus poteramus aderamus aberamus deeramus
eratis poteratis aderatis aberatis deeratis
erant poterant aderant aberant deerant

Future indicative tense

The future tense is the root (ab, ad, de,pot) + the future endings of esse:

ero potero adero abero deero
eris poteris aderis aberis deeris
erit poterit aderit aberit deerit
erimus poterimus aderimus aberimus deerimus
eritis poteritis aderitis aberitis deeritis
erunt poterunt aderunt aberunt deerunt

Perfect Tense

The perfect system as with all verbs, both regular and irregular, is normal. Add the regular perfect, pluperfect and future perfect endings to the 3rd principal part after removing the final -i:

fuî, afuistî, adfuit, defuimus. Possum is slightly irregular: potuistis, potuerunt. Sum is regular in the perfect, and the pluperfect and future are formed like any other verb:

fui fuimus
fuisti fuistis
fuit fuerunt

Present subjunctive

The subjunctive mood: Follow the same rules as with the indicative, using the subjunctive form of sum. Add the prefix to the root: possum will become possim, absum, absim etc.:

sim simus
sis sitis
sit sint

Imperfect subjunctive

Use the infinitive as with regular verbs and the appropriate termini:

essem essemus
esses essetis
esset essent

Perfect Subjunctive

The perfect subjunctive uses the 3rd principal part as with regular verbs and the appropriate termini:
{fu-/potu-/afu-/adfu-/defu-} + -eri- + {-m/-s/-t/, -mus/-tis/-nt} Note that the perfect subjunctive looks a lot like the future perfect forms:

potuerim potuerimus
potueris potueritis
potuerit potuerint

Pluperfect subjunctive

The pluperfect subjunctive uses the perfect active infinitive, which is formed by adding '-isse' to the 3rd principal part: fuisse, potuisse, etc. as with regular verbs. Add the appropriate termini:

potuissem potuissemus
potuisses potuissetis
potuisset potuissent

^ Grammatica




Copyright © 2008, KET Webmaster