How to use in-sentence of “mistakenly”:
+ Unfortunately for the Cullen family, Irina, a vampire from the Denali clan, sees Renesmee and mistakenly informs the Volturi that Renesmee is a forbidden immortal child.
+ The cause of her death was heart failure, from complications related to her illness which caused her to believe mistakenly that she needed to lose weight.VH1, “Behind the Music: Carpenters”.
+ Mockbusters are often made to make customers mistakenly buy the movie instead of the one that they wanted.
+ Truman when the “Chicago Tribune” mistakenly printed newspapers that said Dewey Defeats Truman.
+ He disguises himself as a poor man trying to sell off his jewelry and trinkets, when he comes to the door to find that Hulda’s parents are away from the home, he begins to spin a web of lies that Hulda gets caught in, and mistakenly winds up giving away the Fairies wand, because the peddler convinces her that because the sheen of the jewels is gone, it means the owner has died.
+ Montgomery wrote the book after seeing a newspaper article about a couple that were mistakenly sent an orphan girl instead of a boy, yet decided to keep her.
+ It is often mistakenly called a “rip tide” or “riptide”, which is a flow of water out of an inland lagoon or channel during an ebb tide.

Example sentences of “mistakenly”:
+ The stranger was left in his grave and Daniel was buried at the foot of his wife’s grave, but 16 years later, a gravestone was mistakenly placed over the stranger’s grave.
+ Although it can be mistakenly described as the appearance of a bank movie, he looks like an older person and wears the same company emblem as the main characters around his neck.
+ Astronomers mistakenly thought they had detected the spectroscopic mark of water in the Martian atmosphere, and the idea of life on Mars became popular among the public.
+ When the Union army retreated from Wilson’s Creek, Lyon’s body was mistakenly left behind on the battlefield.
+ Editors often put on a page, mistakenly confusing that with creating a page with the text.
+ Gazeta Olsztyńska, a Polish newspaper mistakenly used one of the pictures for a February 4, 2010 front page story about the Olympics in Vancouver.
+ Ultrasonic cleaners are sometimes mistakenly called supersonic cleaners.
+ For approximately 40minutes on January 31, 2009, “all” search results were mistakenly classified as malware and could therefore not be clicked; instead a warning message was displayed and the user was required to enter the requested URL manually.
+ The stranger was left in his grave and Daniel was buried at the foot of his wife's grave, but 16 years later, a gravestone was mistakenly placed over the stranger's grave.
+ Although it can be mistakenly described as the appearance of a bank movie, he looks like an older person and wears the same company emblem as the main characters around his neck.
+ It was first described and mistakenly identified as an octopus in 1903.
+ A nightclub patron mistakenly believes Martha is a pickpocket who robbed him.
+ Martian Mask: FBI agents mistakenly believe The Mask is actually an alien bent on world domination and do everything to capture him, whilst Putty Thing and Fish Guy go on a road trip.
+ When the king returned, he mistakenly believed Haman had molested his queen, and had him hanged on the same gallows that Haman had prepared for Mordecai.
+ She mistakenly believes that Kevin O’Donnell is a bar owner.
+ In North America, Arrowheads are sometimes mistakenly attributed to the Historic Period American Indians, but are actually from North America’s prehistoric ancestors; some arrowheads date back to over 15,000+ years old.
