When Jessica and Cassidy put up the tree in Jessica's house, Jessica states that it will have been two years less a week that she and Dennis have been dating. When Jessica and Dennis have the serious discussion about their relationship which is a few weeks later, Nick says they have been dating for less than two years. By the time of that discussion, it would have been just over two years according to the earlier conversation between Jessica and Cassidy.
Twenty six to twenty seven minutes into the movie the character Jessica mispronounced a word using the English pronunciation instead of the correct French pronunciation.