Queen Elizabeth II may not watch “The Crown,” the Netflix series with its second season out Friday, but if Her Majesty were ever to queue up an episode and watch Claire Foy play her as a young woman, she just might give it the royal seal of approval.

“A close friend of the queen said that they liked the way in which [Foy] is always asking the politicians awkward, common-sense questions,” says Robert Lacey, a historical consultant on the show and author of the new book “The Crown: The Official Companion, Vol. 1” (Crown Archetype). “Because that’s who she is. She’s very matter-of-fact, very practical.”

And it’s not just the queen’s personality the show gets right.

“The Crown,” created by “The Queen’s” screenwriter Peter Morgan, employs eight fact-checkers, a dialect coach, a jewelry expert and even an on-set etiquette consultant to make sure every detail is in place. Well, with the occasional embellishment or two.

“Maybe there’s a few too many corgis,” says Lacey. “But if Shakespeare could invent witches for ‘Macbeth,’ as far as I’m concerned, Peter Morgan can invent extra corgis for the queen.”

The accent

Dialect coach William Conacher says that nailing the way the real-life Queen Elizabeth spoke as a young woman is essential for getting the character. “When we first started, we said, ‘Should we do such a plummy [aristocratic] accent for the queen? Would that be a barrier for the audience? Would it make her unsympathetic?’ ” says Conacher, who also worked with Helen Mirren when she portrayed Elizabeth II in the play “The Audience.”

“But I thought pretty strongly that the moments [Elizabeth] faces [in the show] are so particular to her life, and the way she reacts to them are precisely because of her social background,” he says.

Conacher didn’t want Foy to do an impersonation of the monarch. Instead, he broke down the physical characteristics and aural quirks the queen uses and worked with the actress on those.

For example, he says, the queen barely opens her mouth when she speaks. So the first thing he had Foy do was relax her jaw but then not allow very much space between her teeth: It immediately got the kind of timbre she needed.

Then, there are the particular vowel sounds.

“The queen doesn’t say, ‘Thank you’; the queen says, ‘Thenk you,’ with the ‘you’ very short,” says Conacher. “I can tell you that was one of the most addictive things to say on the set . . . We would all, the entire crew, go around saying, ‘Thenk yu.’”

Conacher not only works with Foy, he also is tasked with coaching every single actor on set, from helping American John Lithgow channel British Prime Minister Winston Churchill’s bluster in Season 1 to finessing Michael C. Hall’s impersonation of JFK in Season 2. He says sometimes it’s the simplest-seeming things that can trip up actors.

“Poor Matt Smith,” says Conacher of the actor who plays Elizabeth’s husband, Philip, who kept pronouncing the word “was” like “wuz” — instead of something more like whas. “He’d come in and say, ‘I’ve been practicing all night: ‘Wuz!’ And I’d say, ‘No, you’re doing it the wrong way.’ It sounds so stupid because it’s just one little word, but honestly it makes such a difference.”

The history

Lacey, the show’s historical consultant, says that every installment of “The Crown” is based on a real-life episode. A team of researchers go through newspaper articles, books and archives in search of interesting anecdotes or details to send to writer Morgan, who then shapes that material into scripts.

“He will consult me on details, like, what did the little princesses [Elizabeth and Margaret] call their daddy [King George]?” says Lacey. (For the record, they called him Poppa.)

Other times, his role is more abstract.

“In Season 1, for example, there’s a row between Philip and the queen, where he comes running out the door of the bungalow in Australia, and the queen is screaming at him, only to discover they’re being filmed by an Australian camera crew,” says Lacey. “Well, we know that happened, but we had to guess, or Peter had to guess, what went on the other side of the door to provoke such fury. That’s where he’d say to me, ‘Do you think this is plausible?’”

Then there are myriad other “Crown” consultants: There’s an etiquette expert who sits on the set at all times, telling actors the proper time to say “your royal highness” versus “your highness,” versus “your majesty.”

There are historical costume experts who make sure that Foy’s sashes and dresses are worn the correct way, and jewelry experts who make sure that the crown has the right amount of diamonds and pearls. (Though some royal-fashion blogs have pointed out that Foy’s pearls aren’t the knotted ones that the real queen always wears.)

And then there are the props, which also can be quite elaborate.

Next season, says Lacey, “We’ll be coming on to Prince Philip’s building of his barbecue wagon, and we’ve got to get all the details from that. It’s so large it has to be taken out by Land Rover and it’s full of little padded drawers with whiskey and brandy and things like that, as well as all the ingredients. That will be a challenge for the future.”