Is it valid to say: Tu es monstre! Il y a sans espoir!

Bonjour Patrick ! To say "You're *a* monster!", you also need the article in French, which is masculine to agree with "monstre": "Tu es un monstre !" As for "There is no hope", you need to apply the negative "ne pas" to the verb, as such: "Il n'y a pas d'espoir." See in the following lesson why the partitive article (*de l'* espoir = some hope) becomes d' in the negative: Du/de la/de l'/des all become de/d' in negative sentences (French Partitive Articles) I hope that's helpful! À bientôt !