The choice of plural is sometimes left to the user, while in some cases there are differences of meaning:  There are a few genuine irregular plurals in Italian (""). Most of these were introduced in Vulgar Latin, but some derive from irregular Latin plurals. Examples include:  In Italian, altered nouns are nouns with particular shades of meaning. They are divided into diminutives, "vezzeggiativi" (diminutives with kindness and sympathy nuance), augmentatives and pejoratives. Many other alterations can be built, sometimes with more than one suffix: for example, "libro" (book) can become "libretto" (diminutive), "libricino" (double diminutive), "libercolo" (diminutive + pejorative), "libraccio" (pejorative), "libraccione" (pejorative + augmentative). "Uomo" (man), coming from Latin "homo", becomes "om-" in altered forms: "omino"/"ometto" (diminutive), "omone" (augmentative), "omaccio" (pejorative), "omaccione" (augmentative + pejorative). In Italian, an adjective can be placed before or after the noun. The unmarked placement for most adjectives (e.g. colours, nationalities) is after the noun, but this is reversed for a few common classes of adjective — those denoting beauty, age, goodness, and size are placed "before" the noun in the unmarked case, and after the noun for emphasis. Placing the adjective after the noun can alter its meaning or indicate restrictiveness of reference. If a noun has many adjectives, usually no more than one will be before the noun. Adjectives are inflected for gender and number:  Italian has three degrees of comparison: comparative, relative superlative and absolute superlative. The comparative and relative superlative are formed with "più" ("more", "most"); for instance:  Vice versa, inverting the order of the words, it's required to replace "più" with "meno" ("less, fewer"); for instance:  Another comparative form is made with the word "come" ('as', 'like'); for instance:  The "absolute comparative" is formed by placing "troppo" ("too") before the adjective; for instance:   The "absolute superlative", derived from the Latin synthetic superlative in "-issimus", is formed by adding "-issimo" to an adjective: "intelligente" ("intelligent"), "intelligentissimo ("very intelligent"); "sporco" ("dirty") "sporchissimo ("very dirty").