Negation is a bit of a grammar-y word, but it really means making any sentence into a negative - e.g. in English, the negative form of the sentence "I do have a cat" is "I do not have a cat". So, here we have added the word "not" after the main verb, "have". This is a very similar process in Italian - we simply add the word "non" in front of the verb. So, in Italian, when we negate the sentence "ho un gatto", we get "non ho un gatto". Now let's have a go with some different examples...