Italian flag

Adjectives using the preposition 'a'

When you learn new Italian adjectives, you might notice that many of them are picky about the prepositions they hang out with. A large and important group of adjectives connects to their reference points using the preposition a. This can be tricky for English speakers because the direct translation often uses completely different prepositions.

For example, in English you are interested in something, fond of someone, or suitable for a purpose. In Italian, all of these relationships are expressed using a. If you try to translate these phrases word for word, you will likely end up using the wrong preposition. Let us look at how these adjectives work and explore some of the most common ones you will encounter.

Word list
disponibileA2 available disponibile a = available to interessatomA2 interested interessato a = interested in notomA2 famous noto a = known to ugualeA2 same uguale a = same as, equal to utileA2 useful utile a = useful to, useful for adattomB1 suitable adatto a = suitable for adeguatomB1 suitable adeguato a = appropriate for affezionatomB1 fond affezionato a = fond of ben notomB1 famous ben noto a = well known to comuneB1 common comune a = common to, shared by deditomB1 dedicated dedito a = dedicated to dispostomB1 prepared disposto a = willing to, prepared to dispostomB1 willing disposto a = willing to gratomB1 grateful grato a = grateful to inutileB1 useless inutile a = useless to, useless for preparatomB1 prepared preparato a = prepared to prontomB1 prepared pronto a = ready to sconosciutomB1 unknown sconosciuto a = unknown to simileB1 similar simile a = similar to sufficienteB1 enough sufficiente a = enough to vicinomB1 nearby vicino a = close to, nearby accessibileB2 affordable accessibile a = affordable for adiacenteB2 neighboring adiacente a = adjacent to allergicomB2 allergic allergico a = allergic to attentomB2 cautious attento a = careful of, careful about dannosomB2 harmful dannoso a = harmful to disponibileB2 helpful disponibile a = helpful to, obliging to essere sufficienteB2 to suffice essere sufficiente a = to be enough to fedeleB2 faithful fedele a = faithful to idoneomB2 suitable idoneo a = suitable for ignotomB2 unknown ignoto a = unknown to inadattomB2 unsuitable inadatto a = unsuitable for infedeleB2 unfaithful infedele a = unfaithful to lealeB2 faithful leale a = loyal to nocivomB2 harmful nocivo a = harmful to relativomB2 relative relativo a = relative to restiomB2 reluctant restio a = reluctant to riconoscenteB2 grateful riconoscente a = thankful to riluttanteB2 reluctant riluttante a = reluctant to vicinomB2 neighboring vicino a = neighboring limitrofomC1 neighboring limitrofo a = neighboring, adjacent to limitrofomC1 bordering limitrofo a = bordering ortogonaleC1 perpendicular ortogonale a = orthogonal to ostileC1 hostile ostile a = hostile to parallelomC1 parallel parallelo a = parallel to perpendicolareC1 perpendicular perpendicolare a = perpendicular to vicinomC1 bordering vicino a = bordering indifferenteC2 indifferent indifferente a = indifferent to
Connecting to nouns

When these adjectives connect to a noun, the preposition a almost always combines with a definite article to form an articulated preposition, such as al, alla, ai, or alle.

This group includes adjectives that describe physical space or relationships. Words like vicino, simile, uguale, parallelo, adiacente, ortogonale, perpendicolare, and relativo all use a to point to what they are compared to or located next to.

La mia borsa è uguale alla tua.
(My bag is the same as yours.)
Il tavolo è vicino al muro.
(The table is close to the wall.)

You will also find many adjectives describing personal feelings, conditions, or loyalty in this category. For instance, you will use a with affezionato, allergico, interessato, fedele, infedele, ostile, dedito, and indifferente.

Lei è interessata alla musica classica.
(She is interested in classical music.)
Mio fratello è allergico alle arachidi.
(My brother is allergic to peanuts.)
Lui è sempre fedele ai suoi principi.
(He is always faithful to his principles.)
Connecting to verbs

Many adjectives in this family connect directly to an infinitive verb. In these cases, the preposition remains a simple a. This often maps neatly to the English "to do something", which makes it a bit easier to remember.

Adjectives expressing readiness or willingness follow this pattern. Look out for disposto, pronto, preparato, disponibile, restio, and riluttante.

Siamo pronti a partire subito.
(We are ready to leave immediately.)
Il ragazzo è restio a parlare.
(The boy is reluctant to speak.)

You will also use a with adjectives that describe whether something is fit for a purpose, such as adatto, adeguato, idoneo, inadatto, utile, inutile, and sufficiente.

Questa scatola è adatta a contenere i libri.
(This box is suitable for holding the books.)
Non sono disposto a pagare così tanto.
(I am not willing to pay that much.)
Watch out for multiple prepositions

Keep in mind that a is not always the only preposition these adjectives can take. Sometimes the preposition changes depending on whether the target is a noun or a verb, or what role the target plays in the sentence.

For example, pronto and preparato take a before an infinitive verb, but they usually take per when followed by a noun.

Siete pronti per l'esame?
(Are you ready for the exam?)

Similarly, adjectives expressing gratitude like grato and riconoscente use a to indicate the person you are thanking, but they use per to specify what you are thankful for.

Sono molto grato a Marco per il suo aiuto.
(I am very grateful to Marco for his help.)
Summary

A great rule of thumb is to learn the preposition alongside the adjective as if they were a single vocabulary item. Instead of just learning that interessato means interested, memorize interessato a. Treating the adjective and its preposition as a packaged deal will save you from making direct translation errors.