The phrase "thought it improper" is correct and usable in written English.
It can be used when expressing a personal opinion or judgment about something being inappropriate or unsuitable.
Example: "She thought it improper to discuss personal matters during the meeting."
Alternatives: "considered it inappropriate" or "deemed it unseemly."
He thought it improper for an individual to dispose of school property and said he'd look into selling the machines.
When he first heard she was thinking of standing, Orlando says he didn't speak with her for days: he thought it improper to influence her.
There was an increase in women who thought it "wrong to talk about AIDS in a respectable family", and more respondents in 2009 thought it improper to discuss condoms (15.6% vs. 27.4%, AOR 1.9, 95%CI 1.4-2.8, p=0.001).
This is what happens in battle, the film implies, and only a civilian would think it improper.
He said he thought it was improper for the bank to have changed identities on the accounts.
I thought he had conducted himself in a way that demonstrated a strength I had never seen before, but still I thought it was improper".
Mr. Green, asked about that, said: "I always thought it's improper to impute the views of a supporter to the candidate.
"Nonetheless, I think it is improper for outsiders to interfere in the legal processes of Russia".
The opposition leader labelled the arrangement a scam and called on Turnbull to say "he will either continue the scam and that he approves of it, or alternatively that he thinks it's improper and will shut it down".
That isn't good enough for Shorten, who said the prime minister had "questions to answer", and must explain whether "he will either continue the scam and that he approves of it, or alternatively that he thinks it's improper and will shut it down".
I mean, it does not really matter to me, but I think it is improper, all the same.
