"remains polite" is a correct and usable phrase in written English.
It is typically used to indicate that someone is continuing to show politeness in a situation. For example, "The customer, despite her disappointment, remained polite throughout the conversation."
Throughout all the abuse Sara gets from the headmistress, she remains polite and dignified – just like a real princess.
David Rintoul's patriarchal Dickens remains polite to his house guest while nastily pushing his ageing wife, Catherine, out of his life.
That wrench is not in "Battle Studies," Mr. Mayer's fourth album, which, despite its persistent pessimism, remains polite and affable, vulnerable enough to ensure that his female fans — and those are the ones who count — won't stray.
Seya remains polite with Shuichi, though due to their initial meeting, there is always some awkwardness between the two boys.
Always tip! Watch the video to see how one man deals with unexpected things at the restaurant, but still remains polite.
He remains calm, polite and affable; his manner kindly, his reaction to the guilty verdict one of apparent bewilderment.
"Still Alice" remains as polite, as informed, and as cautiously compassionate as the society that it depicts.
He remains unfailingly polite, going so far as to apologize for campaign workers watching a University of Florida football game who booed when Governor Bush appeared on the television screen.
Yet "Dojoji" remains resolutely polite, so its stylistic shifts lack the impact they might have — Yasuko Yokoshi's recent work at New York Live Arts, Belll," with its marvelously startling collision of the same Japanese myth with the 19th-century ballet "Giselle," several times floated tantalizingly through my mind while at the Clurman on Sunday afternoon.
It either becomes an argument where opposing sides never even attempt to understand each other -- or, equally problematic, the conversation remains so polite, so worried about offending someone, that it accomplishes nothing.
