When young Toula and her "friends" are in the car on their way to school, Gus' gloves disappear and reappear numerous times as he is driving.
When they are sitting on Toula's parent's couch, the plastic cover changes. One minute it is covering all of the couch, the next it is only covering the back of the couch.
When young Toula's dad drops her and her friends off at school, and stops her to remind her she "should be proud to be Greek", the window changes position throughout the dialogue.
During the proposal, Toula's hand is on her chest during close-ups of her face, but is caressing Ian's face and moves to her side when the camera is on Ian.
When Toula decides to sit at the table full of blondes at college, she places her brown bag lunch on the table then sits down. In the next shot, she picks up her lunch bag and sets it on the table in front of her again before opening it.
In the Greek Orthodox Church there is an organ playing the wedding march. Eastern Orthodox churches are noted for their custom of eschewing organs or any sort of musical instrument at all.
In the advertising, credits, etc., they replace the "E"s in the word "GREEK" with Greek "sigma"s. But "sigma" is "S", not "E".
In the beginning Toula states that the house has Corinthian columns, but the scrolls that are the hallmark of Ionic columns are clearly visible, and they're a Greek family, so they would never use the combined columns that the Romans made from Corinthian and Ionic column markers.
In the English subtitle of one of the Greek verbal exchanges, "writing" is misspelled as "writting."
In the scene where Gus drives the three girls to school there's a black board visible on Toula's side of the car.
When Toula's mother is talking to her on the phone while peeling potatoes, the sound of her peeling continues when she pauses for a brief moment at the beginning of the phone call.
When Maria is telling her daughter about her life in Greece and why she left, it is obvious that the audio has been re-dubbed.
When Toula sees Ian at the travel agency for the first time, a grey-haired man wearing a blue windbreaker is reflected in the window.
A Canada-Post mail truck is visible in the distance, outside the travel agency window. For that matter, the Pappas Grill opposite the street is a well-known Toronto restaurant on Danforth Avenue.
The women wear their wedding rings on the left hand - Greek Orthodox women wear wedding rings on the right hand.
In the wedding invitation, Portokalos is spelled "Rortokalos" in the Greek section.
The Portokalos house has Corinthian columns which are said to be like those of the Parthenon. In fact, the Parthenon's columns are Doric, which are much older and simpler than the elaborate Corinthian columns.
In the travel agency, Toula is on the phone telling a customer that their reservation is PNR. That is incorrect travel agent lingo - a PNR *is* the reservation itself (it stands for Passenger Name record) - she should have said your seats are confirmed.
Toula calls her mother and says they will be there with Ian's parents in about an hour. Then the man shows up at the back door with a raw lamb.
But once a lamb is on the spit, spit roast lamb can take between 4-6 hours. depending on size.