Duchess Meghan sometimes slips into a British accent and has "adopted certain phrases" after living in the UK with husband Prince Harry.
The 39-year-old former actress - who married Prince Harry in 2018 before the couple moved to the US earlier this year - is said to have developed a mixed vocabulary which amuses staff at their new California home.
A source told The Sun newspaper: "Meghan was the all-American girl before she met Harry, but since living in the UK she's adopted certain phrases.
"Her staff think it's amusing to listen to an American celebrity using Britishisms. She's often heard saying, 'Oh dahling,' to people at home.
"They do have a giggle about it and sometimes they do impressions of her but only in a lighthearted way. It's funny to them."
And the staff already "love" to hear Harry, 35, speaking in his own accent, although they're wondering if he could "pick up Americanisms" as time goes on.
The insider said: "The staff there love to hear Harry's accent, too. They adore him.
"He's very well-mannered and staff were shocked by how down-to-earth he is as a royal. He just wants to live a more normal life now in California and enjoy family time.
"No doubt he'll start to pick up Americanisms soon and will be asking staff to take out the trash."
Meghan and Harry - who have 15-month-old son Archie together - moved into the nine-bedroom property last month, after previously staying in Tyler Perry's Beverly Hills mansion since moving to Los Angeles earlier this year.
The royal couple splashed out $14,650,000 for the 18,000-square-foot home, and the five-acre grounds boast ancient olive trees rose gardens, a tennis court, a tea house, children's cottage and a pool.
As well as the bedrooms and bathrooms, the main house includes a library, office, spa with a separate dry and wet sauna, gym, game room, arcade, theatre, wine cellar and five-car garage, and has reportedly updated with the latest Lutron lighting systems and Crestron, including iPad control.
There is also a two-bedroom guest house, and for added privacy, there are multiple access gates before anyone can get near the abode.