The phrase "alert person" is correct and usable in written English.
It can be used to describe someone who is attentive, watchful, or quick to notice things around them.
Example: "In emergency situations, it's crucial to have an alert person on the team who can respond quickly to any changes."
Alternatives: "vigilant individual" or "attentive person".
I need to be the most alert person on the planet.
During stage 5 sleep the EEG pattern of brain-wave activity appears very similar to the brain-wave activity of an awake, alert person.
This was an autonomous, fully alert person making a decision about his own final days — the very situation she had spent her career defending.
Nor is there what a morally alert person could describe as a natural "right" or a liberty to own lethal weapons designed only for murder — every remotely free society, other than our own, is astounded by the notion that it might be.
Questioned about an affair in a deposition to be seen by your spouse, most people would have lied, and though scholars and lawyers may debate if there are circumstances where such a lie can fairly be called criminal, a morally alert person might see that a wrong that nearly every person would commit in the same circumstances is something closer to a human right.
In the mortgage bubble crisis, pretty much everyone was asleep at the switch, relying on triple A ratings and other "objective" indicia of stability when any alert person would see that the loans were garbage. .
This will alert persons working around your equipment that you are reversing the machine.
General examination revealed a rousable individual who appeared somewhat confused, but was alert to person and place.
"But we appreciate the fact that an alert security person from Condé Nast did".
For example, at Dynamicsoft, a company in East Hanover, N.J., officials have discussed how presence software, wireless hand-held computers and G.P.S. tracking could alert a person when a friend happened to be a few blocks away.
If someone comes in shortly before such an occasion and shows interest in an item but doesn't buy it, the store's sales staff is trained to alert the person's spouse about this possible gift.
