[noun in nom.] + [linking verb] + [adj. in nom.]

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Although the entire verb is technically permissa est, the pluperfect passive indicative of permittere, permissa functions like a predicate adjective, with est as the link to res publica.

The only caveat is that permissa est must be translated in the perfect (was allowed) and not in the present (is allowed).

NOTE:  Nominative adjectives used as predicates are often called predicate adjectives.

[noun in acc.] + [linking verb] + [adj. in acc.]

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In this example, constrictam is accusative in order to modify conspiracy (coniurationem).  Conspiracy is accusative because it is the subject of the indirect statement introduced by non vides.

If this were direct statement, we would have something like this:  coniuratio est constricta, where constricta is a predicate nominative.  The addition of the "head" verb mandates a change from predicate nominative to predicate accusative.

teneri (to be held), the passive of tenere, is basically the same as esse.  It is the linking verb between coniurationem and constrictam.

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In this example we have the same situation as above:  clementem and dissolutum are the predicate accusatives modifying me;  esse and videri are the linking verbs.  All are governed by cupio in indirect statement.

NOTE:  If the subject is nominative, the predicate must also be nominative;  likewise for accusative subjects.  There can be no mixing and matching of cases, no nominative subjects with  predicate accusatives, or vice versa.

[pres. stem of verb] + [-nd-] + [1st or 2nd decl. adj. ending]

Example:  amare, to love = ama + nd + a (nom. sing. fem.)

amanda, she who must be loved.

As you can see, there are as many gerundives as there are cases, numbers, and genders.  Since gerundives can be masculine or feminine or plural, they are easily identified as adjectives.  Conversely, if you see what looks to be a gerundive all by itself, and in the neuter singular, you are probably looking at a gerund, which is a verbal noun.

Gerund or gerundive?, that is the question.  In theory,  the  following sentence, which utilizes the gerund, makes grammatical sense.

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amando governs libros as its object.  In practice, however, such constructions are rare.  Here is what Cicero would have written, using the gerundive:

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In this sentence, libros becomes libris.  That is, what was formerly a direct object is put into the case of our theoretical gerund (amando), an ablative of means.  The gerund is then replaced by a gerundive, amandis, which modifies libris in case, number, and gender.  This is the noun + gerundive construction, and it is favored over gerund + noun.

NOTE:  The above translation is very literal.  For the sake of convenience, if not sanity, we would translate as, She lives by means of loving books.  In other words, we translate as if we had gerund + noun.

Here is a noun + gerundive sentence from our reading:

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The key words are senatus habendi locus, lit. place of the senate to be convened.  This phrase replaces locus habendi senatum, gerund + noun, where habendi would take senatum as a direct object.

The reason why senatus habendi is identifiable as noun + gerundive is that senatus is clearly genitive, which means that habendi must be an adjective.

[ad] + [noun in acc.] + [modifying gerundive] + [verb]     -or-

[noun in gen.] + [modifying gerundive] + [causa] + [verb]

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The prepositions ad or causa with the noun + gerundive construction denotes purpose.

Here audaciam is the object of ad, and is modified by both deponendam and confirmandam.  To bring out the gerundives, we might translate, You live not for the purpose of (ad) putting aside your boldness, but for the purpose of strengthening it.

You might have thought deponendam and confirmandam were gerunds because they both follow ad directly.  Their feminine endings, however, reveal that they are adjectives, and so gerundives.

causa, which is the really the ablative singular of the noun cause, is used after  genitive nouns and gerundives:

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Compare this expression of purpose with subjunctive purpose clauses, supines, and relative clauses of purpose.

[nom. noun] + [linking verb] + [gerundive predicate] + [dat. agent]

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The passive periphrastic, which expresses duty or obligation, is nothing more than the gerundive functioning as a predicate nominative after a linking verb.

In the above sentence, verendum modifies hoc in case, number, and gender (nom. sing. neut.)  Usually the linking verb is in the present, not the future, tense, like so:  hoc est verendum, which would mean, This is to be feared, or even, This must be feared.

mihi is a dative of agent, which is the norm with passive periphrastics.

NOTE:  In the original Latin, what Cicero has to fear is actually a subject noun clause.  See also the entry on clauses of fearing.