The Knights who say Ni are rumoured to be connected to the mock subtitles in the opening credits which advertise Sweden. In the Swedish language, "Ni" is second person plural (the equivalence of the English plural "you") and used to be the proper form for adressing people outisde your circle of family and friends. This was however abandoned during the late 1960-ies/early 1970-ies in the so-called "du-reform" ("du" being the second person singular form). According to the rumor, the joke with the knights saying "Ni" and people's negative reaction to it is a mockery of how the "ni" form was rejected by almost all Swedes, and thus no longer acceptable. Over the years the Pythons have gone back and forth between denying that the rumour is true, and confirming that it is indeed true. [Trivia is not about unsubstantiated rumours.]

The Knights who say Ni can not stand to hear the word 'it', yet the Head Knight of Ni says 'it' three or four times, and there is no reaction from the other knights of Ni. [The Knights Who Say "ni" become the Knights Who Say "eeke eeke eeke ptang zoo boing" and these particular knights are weak against the word "it", not the Knights Who Say "ni"]

In the scene inside the Cave of Death, the priest reads the 'Last Words of Joseph of Arimathea'. As he reads them, his eyes go from left to right. If it was Aramaic like he said, he would read it from right to left. [The priest that reads the writing on the wall does read from right to left - his right to left, he reads from the AUDIENCE'S left to right. The camera shot is as if the audience is the wall he is reading from and so his eyes move the correct way for reading Aramaic.]

In the French castle scene, when the Frenchmen are exiting the castle to get the wooden rabbit, one of the Frenchmen has a hole in his armor between his legs. [In reality Mediaeval armor was wrought with imperfections, okay, this imperfection was of a humorous nature but that does not necessarily make it a mistake. ]

At the witch's trial, during the long pause while they are thinking of something that also floats in water (a duck), Eric Idle is desperately trying not to laugh - he even goes as far as biting the top of his sythe to cover his giggles. This is mentioned in the commentary on the DVD and once you've noticed it, you won't be able to watch the scene again without your eyes glued to poor Mr Idle. [He might have been trying to hide laughter, but he did such a good job of it as to be unnoticable unless you already knew. He never breaks character, and the scythe-biting can simply be interpreted as his dim-witted character trying hard to think.]

In the cave with the inscriptions left by Joseph of Arimathea, after King Arthur corrects Sir Lancelot about St. Arrghs/St. Ives, Lancelot's voice says "That's right," but it's Sir Galahad that moves his mouth, not Lancelot. [Sir Lancelot actually does say it - you just can't see it well because of the lighting. Sir Galahad is simply licking his lips or something at the same time.]

In the final scenes of the film, a George Cross [or 'England flag'] is flying from the French-occupied Castle Aaaaargh. [This is simply a ploy by the French to trick the English into thinking the castle is allied. Not a mistake, exactly.]

The animations (and the DVD subtitles, but the animations particularly) frequently change between the spellings 'Lancelot' and 'Launcelot'. Compare the book animation where we are first introduced to Sir Lancelot to the animation that shows 'the Tale of Sir Launcelot'. [It's obviously a deliberate joke, so deliberate in fact that it cannot be deemed a deliberate mistake.]

In the final scene, as the black police truck arrives, you can see a boom microphone reflected in the side of the truck. Seen on the VHS edition. [They also say "turn that camera off" followed by a cop grabbing the camrea. I don't think that the boom mic is a mistake cause right after this it's revealed that this is actually a movie being shot.]

When the knights are talking with Tim about the Cave of Death, Tim says that the inscription describing the location of the Grail was written by "Alther Bedwin of Reggeth," yet it's said elsewhere in the movie that the inscription was written by Joseph of Arimethea. [Tim does not say that the inscription was written by Alther Bedwin of Reggeth, he says that the inscription "was the last words SAID by Alther Bedwin of Reggeth". Joseph of Arimethea was there when he said it and wrote it down.]

When the police are going to arrest the knights at the end, you can see a reflection of the crew on their cars. [The 'crew' are part of the scene - it's a news crew filming the arrests. At the end the police sergeant stops filming by putting his hand over the camera lens.]

When the knights are walking with Tim the Enchanter, three new knights appear. [That's because a year had passed since we last saw the knights, King Author may have recruited new knights during this time.]

When Arthur and the Black Knight are fighting, and Arthur chops off the Knight's second arm, Arthur swings his sword horizontally, but the Knight's wound is almost vertical. [It's very straightforward - he has his arm against his side when Arthur's sword slices horizontally through his upper arm, then he rotates his arm, turning the stump through 90 degrees and making the wound vertical.]

When Sir Lancelot is running to the castle to save the prince, the same shot is shown many times so he runs up the hill, then appears at the bottom at the start of the next shot. [Yes. It's an intentional comedic device, parodying similar scenes in other movies, not a mistake. Even the guards appear bemused that he seems to be taking so long to get to them - and then he attacks them suddenly, with no interlude where he's just 'nearby.']

Tim the Enchanter completely vanishes after the knights charge the killer rabbit. [No, while they're attacking it we see him laughing and walking off.]

In the scene where King Arthur fights the black knight, he cuts off his last leg. But when it shows the black knight he doesn't even have a bottom. [If you look closeley at the legs that fall off of the Black Night, you will see some of his bottom coming off with the legs.]

In the scene were King Arthur fights the Black Knight, prior to Arthur's arrival the Knight is battling some unworthy adversary. When he is defeated he falls to the ground near the Black Knight's feet, but when Arthur approaches the corpse is nowhere to be seen. Even in wider shots during their fight, he's nowhere. [You can see the dead body. He lies in the trench; in the left of the screen. ]

During the scene where Brother Maynard is reading the carving in the cave, you can clearly see a different person playing Sir Robin. Robin is normally played by Eric Idle but in just that scene it is a totally different person. (Eric Idle also played Brother Maynard. A similar thing happens in the previous scene - John Cleese played Tim The Enchanter as well as Launcelot, so the latter didn't appear in that scene). [The mistake is not quite true, because Lancelot does appear, but to disguise the unknown actors face, Lancelot is wearing his helmet.]

The sequence order of each knight's tale doesn't work. Lancelot rescues Galahad before his tale begins and then we don't see Galahad again but you know that he stayed with him because it says the other knights meet up with the two after. [I don't think the tales are supposed to be told in chronological order. In fact, I believe they're in alphabetical order (Galahad, Lancelot, Robin).]

When King Arthur arrives and the Black Knight is fighting someone else, the Black Knight stabs his victim straight through the helmet between the eyes. When he removes his sword the sword is through the helmet across his nose, a movement of 90 degrees. [The green knight's head is just turned.]