The phrase "cautioned me that" is correct and usable in written English.
It can be used when someone is warning or advising you about something specific.
Example: "She cautioned me that the road ahead was slippery due to the rain."
Alternatives: "warned me that" or "advised me that".
They cautioned me that it might take several months to arrange a trip.
He cautioned me that I had accepted a very difficult job: "You're black, you're female and you're a civilian.
Now, the doctors cautioned me that while my immune system was still very weak, my brother Adam's healthy cells were beginning to engraft in my bone marrow.
When I told my mom about this article, she cautioned me that 'the last thing our country needed right now was more hate.' As usual, she's right".
He did not say much else, and when, a few days later, I was scheduling an interview with him, his spokesperson, Kim Akhtar, cautioned me that he wouldn't talk about the report.
It was a joy to play with him this year and he's only going to continue to get better," Willis said as a fellow reporter on the carpet cautioned me that Willis has a 100 hitting power on the game, so I may not want to suggest that anyone should outrank him.
Recently a friend told me that he and his wife were expecting a baby, cautioning me that this news was confidential.
"But they also caution me that on the emotional side of this there are a lot circumstances that cause these things to be very carefully investigated to make sure that the whole truth is out there".
Most of my hiring-manager friends like to see skills in evidence on the CV, but they caution me that it can paint you into a box, so you should adapt your skills and techniques section to the job you are applying to.
They'd caution me that it's suicide in today's market because people won't listen to something that's over 35 minutes.
He acceded to my request, only cautioning me that I must confine myself to silent observation and refuse any temptation to speak.
