please provide an example of an appropriate syllogisms that match the meaning of the arguments themselves and then tell us whether the sylllogisms

please provide an example of an appropriate syllogisms that match the meaning of the arguments themselves and then tell us whether the sylllogisms are valid and, tell us why the invalid one or ones are invalid. 

    Since only radicals want to subvert the duly constituted government of a country, this man can't be a radical because he wants to preserve the government of the country.