意大利语是一门形态变化丰富的语言，九大词类中有六大类词有形态变化。句子中，人称、词性、时态都要保持一致。意大利语语法很复杂，不掌握一定的语法知识，就很难进行语言实践。但是只要打好基础，学好动词变位，那么就可以无师自通。
O mangiar questa minestra o saltar questa finestra.
English translation: Either eat this soup or jump out this window.
Idiomatic meaning: Take it or leave it.
Occhio per occhio, dente per dente.
English translation: An eye for an eye, a tooth for a tooth.
Ogni bel gioco dura poco.
English translation: Every good game lasts a short while.
Idiomatic meaning: All good things come to an end.
Oggi in figura, domani in sepoltura.
English translation: Here today, gone tomorrow.
Ogni medaglia ha il suo rovescio.
English translation: There are two sides to every coin.
Ogni regola ha un' eccezione.
English translation: There is an exception to every rule.
