When Romeo drinks the poison, he first opens the bottle, says what he has to say and in the next shot he opens the bottle again before he drinks the stuff.
Juliet's "blood" on the tomb moves around from shot to shot.
Mr. Wabash (the tailor as the Prince of Verona in the play within the film) bows as he finished the play, and then raises his head quizzically twice - once to silence, despite someone applauding in the background, and once to storming applause.
One of the main plots involves William Shakespeare creating the story of Romeo & Juliet, making it up as he goes along. In fact, these characters and their basic story were written about before Shakespeare was born, and he was adapting the older tale for the stage. The filmmakers knew this.
In the end, the Queen says: "Those whom God has joined in marriage, not even I can put asunder." This is wrong. The Queens (late) father, Henry VIII, broke with the Roman church, because he wanted his own marriage to be dissolved and the Pope refused. Since then, the English monarch is head of the Church of England, so Elizabeth could have changed the status.
Philip Henslowe (Geoffrey Rush) is depicted as being constantly in debt, yet the opposite is true - money lending was one of his professions. The filmmakers knew this.
At the very end of the movie, Shakespeare is writing the beginning of Twelfth Night. On the paper, he starts Act 1 Scene 1 with a speech by the character Viola. But Viola does not appear until Act 1 Scene 2 (and in fact speaks first in that scene).
Biographical details of Shakespeare's life, especially his wife and children, ignored for the sake of dramatic license.
Near the end the Queen commands Wessex to pay off the wager of 50 pounds which Viola carries in a pouch. At that time, a British pound coin would have contained one troy pound of silver (hence its name). A troy pound weighs approximately 75% of a normal pound, and would therefore mean the sack she is carrying would be very heavy, much heavier than it appears to be in the movie. However, the pouch that Wessex hands over is the one he received from Viola's father when he asked for 'fifty pounds in gold' - gold, being much more valuable than silver would require a smaller mass for the same value.
The sound of the tambourine, played by William Shakespeare with the musicians at the dance where he meets Viola, continues after he has stopped playing. However, given that Will was not originally part of the music group, it is reasonable to assume that there is a second tambourinist somewhere.
William Shakespeare's Romeo & Juliet is generally thought to have been performed for the first time in 1595 or 1596. Shakespeare in Love (1998) has it performed in 1593, but this is part of the "secret history" which the film is "discovering".
When William Shakespeare and Viola are in bed together the morning after their first tryst, just as Will falls off the bed you can see that he is wearing a pair of black shorts.
In the final credits, the clouds in sky don't move or change shape at all for the whole length of the shot; revealing that a still picture is used in the background.
Viola, living in 1590s London, has shaved armpits.
When Will and Viola are in bed together the morning after their first tryst, the bed sheets are pulled to provide concealment in such a way that only someone not in the bed (and off camera) could physically do.
The Queen commands a comedy for Twelfth Night and Will and Viola sketch out the plot of the play Twelfth Night. That play was written some five years after Romeo and Juliet, with several plays intervening.
In the 1590s, Wessex owns "tobacco plantations in America". There were neither tobacco plantations nor English colonies in America in the 1590s. The Roanoke colony at North Carolina (called Virginia at the time) failed in 1587, and tobacco monoculture did not begin in Virginia until after 1607. The filmmakers knew this.
Viola hears the cock crow and refers to it as a rooster. The word rooster is not recorded before 1772 and is said to be an American coinage to avoid the associations of the older word. Even today it is rarely used in the UK.
Shakespeare is at a tavern early on in the film. The tavern has glass "onion" shaped wine bottles on a shelf. These bottles of the "onion" variety did not exist until the late 17th, early 18th century.
Viola's nurse is shown in a rocking chair. Rocking chairs were invented in America in the early 18th century, and first appeared in England in 1725.
Mr. Wabash the tailor as the Prince of Verona in the play within the film gives the final speech of the last Act ("Never was a story of more woe..."), then bows to the audience. In the side shot that follows, an audience member to his right is clearly applauding, but no sound is audible, as the scene is supposed to be uncomfortably silent while the actors wonder why the audience isn't applauding.
In the opening scene, Mr. Fennyman (Tom Wilkinson) and his henchmen Mr. Frees (Tim McMullan) and Lambert (Steven O'Donnell) are torturing Philip Henslowe (Geoffrey Rush) due to an unpaid debt. Henslowe offers to cut Fennyman in on the profits from a new play by William Shakespeare. We hear Lambert, off-camera, say, "I think I've seen it," but it appears the on-camera Mr. Frees is actually mouthing the words. The shot then cuts to Lambert, who says on-camera, "I didn't like it."
The audio for the choirboys at the church service is a line ahead of the visual.
William Shakespeare/Romeo tends to Ned/Mercutio by kneeling to Mercutio's right, and, in doing so, violates the first "rule" of stage acting, which is to never hinder the audience's view of the stage or the actors.
Will talks of acts and scenes but his work wasn't organised in that way until 100 years later by the publisher Nicholas Rowe.