The phrase "a certain sign of" is correct and usable in written English.
It can be used when indicating that something is indicative or suggestive of a particular condition or situation.
Example: "The sudden drop in temperature is a certain sign of the approaching winter."
Alternatives: "an indication of" or "a clear signal of".
The princess herself is a dark-haired stunner who makes the prince drop his teacup (a certain sign of true love).
There wasn't a sewing machine needle or bobbin in the basket, and the jar full of mismatched shirt buttons was a certain sign of repair work.
The White House announced in advance Mr. Clinton's meeting with Ms. Reno to discuss Mr. Sessions's future and said the President and Ms. Reno would appear jointly in the White House press room, a certain sign of his dismissal.
Increased TEWL values indicates a skin dehydration process [29] but if the values are not very high above the limit increased TEWL values do not indicate a certain sign of noxiousness.
That billionaires are increasingly common is a certain sign that the lot of the American worker has never been better.
He was looking for instances in which a certain sign "caused" an increased risk of a particular ailment.
It's an almost certain sign of impending relegation, particularly when it's a player who has a bit of history with your club.
EXPERIENCED rail travelers recognize it is an almost certain sign of delay when fellow passengers abandon the train and strike off into the surrounding mountains on foot.
FreshDirect recently received a $189 million investment to expand outside the New York-metro area, a certain sign that the brand exemplifies some of the most effective and strategic approaches to retaining and engaging customers.
The new smaller family sedan will probably have a Mazda platform and a Euro design an almost certain sign of disaster to come.
Also, more than half of the brittle stars, a relative of starfish, found clinging to the sea fans were partially or completely bleached white, another certain sign of stress, says Fisher.
