"confirms the notion" is a correct and usable phrase in written English.
It means to support, validate, or prove a belief or idea. You can use it when discussing a belief or idea that has been verified or proven to be true. Example: The study's findings confirm the notion that exercise has numerous benefits for both physical and mental health.
This just confirms the notion that this country has the best justice money can buy.
"It confirms the notion that the economy was weak headed into the third quarter," said Richard Berner, chief economist at Morgan Stanley in New York.
"I have long suspected that the ruling party was a bunch of power-abusing hypocrites, and that encounter merely confirms the notion," Chew says.
The band's first album, 1981's Send Me a Lullaby, confirms the notion that debuts usually present the least refined version of a group, but even here the Go-Betweens still sound more cultivated than most of their indie contemporaries.
The announcement, made last Sunday, that the Party is proposing to abolish term limits for the Presidency further confirms the notion that Xi aims to be something other than just another leader in a parade of apparatchiks.
There's always something pleasing about the sight of stars mucking about in costume – it confirms the notion that movie-making is essentially a lark, however much detailed information we might have about to the contrary – and there are several other such shots here.
Our observations confirmed the notion that Israeli fire damaged the cemetery.
It also seemed to confirm the notion that Quebec produces a more dashing and dynamic brand of politician than the usual stodge.
In the very short term -- defined as five days surrounding the announcement of the deal -- the data seemed to confirm the notion that more debt is a good thing in Wall Street's eyes.
And because the staff -- from the housekeepers to cheerful, avuncular Ted Tyler himself -- have been unfailingly kind and solicitous, further confirming the notion that you have just visited a parallel universe.
That might confirm the notion that sex is an absolute necessity in the long run, but for the puzzling existence of the bdelloid rotifer, a species that has been asexual for 85 million years.
