Final answer:
The proper adjective formed from the proper noun 'Switzerland' is Swiss. Adjectives modify or describe nouns, and in this case, 'Swiss' describes the origin or quality of the chocolates.
Step-by-step explanation:
The proper adjective formed from the proper noun 'Switzerland' is Swiss. So, the sentence would be: Swiss chocolates are delicious. Adjectives modify or describe nouns, and in this case, 'Swiss' describes the origin or quality of the chocolates.