Compound nouns are nouns made up of two or more words:
- Portafortuna (lucky charm)
- Caporedattore (editor-in-chief)
- Dopocena (after dinner)
- Messinscena (staging).
The elements that compose them can belong to various grammatical categories, including nouns, adjectives, verbs, adverbs, and prepositions.
Compound nouns form the plural depending on the type of words from which they are formed.
1. Noun + Noun
The plural is formed as if they were simple nouns; only the ending changes:
Singular: L’arcobaleno (rainbow) – La ferrovia (railway) – Il cavolfiore (cauliflower) – L’autostrada.
Plural: Gli arcobaleni – Le ferrovie – I cavolfiori – Le autostrade.
When the nouns are of different genders, the plural is formed by changing the ending of the first element:
Singular: Il pescespada (swordfish) – Il caposquadra (team leader).
Plural: I pescispada – Il capisquadra
Il pescecane (dogfish) has two plurals (I pescecani – I pescicane)
Some nouns are invariable:
Singular: Il cruciverba (crossword) – Il fondovalle (valley bottom) – Il crocevia (crossroads).
Plural: I cruciverba – I fondovalle – I crocevia.
2. Noun + Adjective.
Both elements are put in the plural:
Singular: La cassaforte (safe) – Il pellerossa (Red Indian) – Il caposaldo (cornerstone) La terracotta (terracotta).
Plural: Le casseforti – I pellirosse – I capisaldi – Le terrecotte.
Exceptions:
Singular: Il palcoscenico (stage) – Il pianoforte (piano) – Il camposanto (cemetery) – Il pellerossa (Red Indian).
Plural: I palcoscenici – I pianoforti – I caposanti – Il pellerosse.
Note that pellerossa has two different plurals; both are correct.
3. Adjective + Noun
Only the second element is put in the plural:
Singular: Il francobollo (stamp) – Il bassorilievo (bas–relief) – Il biancospino (whitethorn).
Plural: I francobolli – I bassorilievi – I biancospini.
Exceptions:
Singular: Il purosangue (thoroughbred) – Il mezzobusto (half-length) – Il bassofondo (shoal/shallow) – L’altopiano (plateau).
Plural: I purosangue – I mezzibusti – I bassifondi / I bassofondi – Gli altopiani / Gli altipiani.
4. Preposition + Noun
They normally modify the ending:
Singular: Il contrabbando (smuggling) La soprattassa (surcharge) Il sottufficiale (non–commissioned officer).
Plural: I contrabbandi – Le soprattasse – I sottufficiali.
Or they remain unchanged:
Singular: Il doposcuola (afterschool) – Il fuoribordo (outboard) – Il sottoscala (understairs).
Plural: I doposcuola – I fuoribordo – I sottoscala.
5. Noun + Preposition + Noun
The plural is formed by changing the ending of the first element:
Singular: Il ficodindia (prickly pear).
Plural: I fichidindia.
6. Verb + Plural Noun
Both elements remain unchanged:
Singular: Il cavatappi (corkscrew) – L’apriscatole (The can opener) – Il guastafeste (mood breaker) – Il portalettere (postman) – Il tagliacarte (paper cutter).
Plural: I cavatappi – Gli apriscatole – I guastafeste – I portalettere – I tagliacarte.
7. Verb + singular feminine noun.
Both elements remain unchanged:
Singular: Il portacenere (ashtray) – Il cavalcavia (overpass) – Il parapioggia (rain cover) Il bucaneve (snowdrop) – L’aspirapolvere (vacuum cleaner) –
Plural: I portacenere – I cavalcavia – I parapioggia – I bucaneve – Gli aspirapolvere.
8. Verb + singular masculine noun.
Only the second element is plural:
Singular: Il portafoglio (wallet) – Il passaporto (passport) – Il battibecco (bickering) – Il grattacapo (headache/trouble) – Il parafulmine (lightning rod).
Plural: I portafogli – I passaporti – I battibecchi – I grattacapi – I parafulmini.
But there are exceptions for nouns that remain unchanged in the plural:
Singular: Lo spartitraffico (traffic island)– Il parasole (sunshade)– Il portasapone (soapdish).
Plural: Gli spartitraffico – I parasole – I portasapone.
9. Verb + Verb or Verb + Adverb
Both elements remain unchanged:
Singular: Il dormiveglia (half asleep) – Il saliscendi (ups and downs) – Il parapiglia (turmoil) Il lasciapassare – Il buttafuori (bouncer) – Il posapiano (lethargic) .
Plural: I dormiveglia – I saliscendi – I parapiglia – I lasciapassare – I buttafuori – I posapiano .