Je voudrais essayer cette robe dans une taille plus grande.

Pronunciation: zhuh voo-dreh eh-say-yay set rohb dahn oon tye pluh grahn.

Meaning: I would like to try on this dress in a larger size.

This polite request uses the conditional tense and is essential when shopping for clothes in France—fitting rooms are common, and French shoppers always ensure the proper fit before purchasing.