The phrase "untrue about" is grammatically correct and can be used in written English.
It is usually used to refer to statements or information that is false or incorrect. Here is an example sentence: "It is completely untrue about John being fired from his job. He actually received a promotion last week."
Her mother told her friend a number of stories, most of them untrue, about her lack of roots.
"You made a public statement that was untrue about his resignation," Mr. Castello said of Mr. Goldsmith's departure.
"He's said a number of things that are untrue about his own record and about mine," he said.
If you write something defamatory or maliciously untrue about another person in an autobiography that you intend to publish, consider changing his or her name (if still living).
It was not untrue about the fleas or the smell, or the responsibilities, either, but none of that was why she went on saying no.
There is very little information, true or untrue, about me on the web because I give so many evasive non-answers – like some of these.
They are telling true stories about their family members and untrue stories about GOP legislation.
Or about your colleagues who spread untrue rumors about you, but how you kept your cool.
Rid yourself of the myth that mentally ill people are violent.[1][2][3] The media often spreads untrue stereotypes about this, and it says nothing about your child.[4][5].
I don't always tell people about my upbringing because they sometimes make untrue assumptions about me: that I don't have mastery of the English language, that they can hear my French accent, etc.
His only frustration, Mr. Kelly said, was repeatedly reading untrue stories about things Mr. Trump said, or of people who are about to be fired.
