The aim in this paper is to elucidate the system of word structure in English and Italian through the Italian compound noun and the English expression. In case of neologizing, it is argued that the Italian words are lexicalized by adding the noun to the suffix and by making the compound word of the noun phrase (n+agg / n+p+n), and the English words are lexicalized by the N + N compound. This presents the character of the lexical systems in both languages.