An interjection is a word or expression often given increased emotive value in the stream of speech.
Although a interjección can form a complete sentence (that is to say, expressing a thought with no need of a subject and a verb), one can often also be inserted within an sentence, separated generally by commas of the rest of the sentence. Interjections are rarely used in formal or business writing. In print interjection is usually followed by an exclamation mark or a comma:
You can see a list with the Ten more used Italian Exclamating Expressions