In the start of the movie when Sophie is leaving work her shirt goes from being tucked in, to untucked, to tucked in again between shots.
When Sophie and Charlie are at an outside café eating ice cream they both go from having 2 scoops, to 1, to 1 and a half, to 2.
When Charlie arrives in Verona to meet Sophie, the car turns right and stops on the left side of the street. However, seconds later the car is parked on the right side when he opens the door and exits the car.
When Sophie learns Charlie's parents died as a child, a woman in dark boots passes them up the road. As the scene progresses the same woman and her friend walk past the camera in the same direction.
When Sophie first visits the Juliet Secretaries' office, she and Isabella look out the window down at the street where they see women walking into Juliet's garden. In this shot the window blinds are tilted downward, which allows them to look down from the second story to the street. A moment later the scene changes to Sophie and Isabella talking, and the blinds are now tilted upward, which would block the view to the street below.
As soon as the main actors arrive in Italy mandolins and tarantellas
are to be heard in the sound track. This is clearly wrong.
Verona is in the north of Italy, Tarantella is traditional music around Neapel (there are more than 600 km between these 2 locations).
When Charlie is talking to Sophie, after Lorenzo rides up on a brown horse, Charlie says that Lorenzo "rides in at the last moment on a white horse". No doubt, Charlie meant the line metaphorically.
Charlie Wyman is Claire Smith's grandson, the son of her son, but his last name is different than hers. If she was only married once, per the plot, then her current last name should also be her son's and her grandson's. However, this is not a goof. The name "Claire Smith" was written on Claire's letter to Juliet, which Claire wrote back in 1957, when she was only 15 years old; she wasn't married yet at that time. In other words, "Smith" is Claire's maiden name. So after her husband died, she apparently chose to change back to her maiden name, and that explains the difference.
When Claire is walking towards Lorenzo the first time they meet in the vineyard, shots of Claire show the sun coming from her right in the late afternoon, but shots of Lorenzo show the sun coming from HIS right (what would be her left), and nearer the middle of the day.
When Sophie is texting Victor, her keystrokes don't correspond to the text that appears on her phone.
When Charlie (Christopher Egan) arrives in Verona to meet Sophie (Amanda Seyfried), you can see the car turning on the right and stopping on the left side of the street. However, seconds later the car is parked on the right side, when he open the door and exits the car. So, in the first shot, the scene was flipped (left-to-right) and later the car plate, and the plates "Banca Populare di Verona" were flipped by CGI. You can notice the details of the car before and after he stops, where the stuff were flipped like exhaust, windshield wiper, also all the things around the place.
When Charlie is in hot pursuit of Sophie on her way back to the city, he sets off less than five minutes after her car ride departs. Sophie is shown being driven at an average speed, and Charlie is shown hurrying, yet he doesn't catch up to her until she has already been dropped off back at her vacation rental, and had time to climb the stairs, take off her shoes, and stand leisurely out on the balcony.
As "Julia" is walking in Verona she is 'greeted' as an American girl,
as if she has a label on her forehead, and the type of dialectal inflection is from the south of Italy (also the working would be used in locations which are 370 miles more to the south than Verona or Veneto). Verona is really not a southern city.
When Sophie is on the balcony at the end, Charlie hears her heels clicking and turns around. We can also hear the heels. But she is not wearing any shoes while on the balcony.
When Sophie is in Victor's restaurant kitchen to announce her going back to Verona, Victor sends all the kitchen employees out of the kitchen. While the employees are there, there are cooking sounds. After the employees are gone, the cooking sounds are gone but all the cooking is still happening in the background.
When driving around Italy, looking for Lorenzo, they are alternately shown driving on the left and right sides of the road. In Italy they drive on the right side of the road. This may be due to some frames being flipped (left-to-right).
When Victor takes Sophie's telephone call during the wine auction he mentions an auction of Sauternes. Sauternes is a wine from the Bordeaux region of France and would not be auctioned in Italy.
When Claire reads Sophie's letter at the wedding reception, she doesn't read the entire letter. She completely skips the first paragraph in which Sophie apologizes for not responding sooner.