The phrase "allow them to fall" is correct and usable in written English.
It can be used in contexts where you are giving permission or enabling something to happen, often referring to letting something drop or fail.
Example: "In order to learn from their mistakes, we must allow them to fall and pick themselves back up."
Alternatives: "let them drop" or "permit them to fail".
You allow them to fall off a swing or a climbing frame because that's important.
We don't want to allow them to fall through the cracks and become statistics".
Allow them to fall from the mouli into a roughly conical pile in the centre of a plate.
"When I have lost confidence in people, I deliberately allow them to fall by the wayside," Piëch once said.
Note that the supplemental information pages were all drafted as images to carefully manage the placement of periods, and never allow them to fall at the end of a line unless they were at the end of a paragraph.
WASHINGTON — Despite President Obama's warning to Syria not to use its arsenal of chemical weapons or allow them to fall into the hands of extremists, the administration's options for intervening remain limited by what its officials have described as a simple calculus: It would make the conflict even worse.
I slid these items off the needle, allowing them to fall into a bowl of cold potato soup.
Recent reports have argued for "counter-cyclical" capital raising bank capital requirements a lot in good times, while allowing them to fall somewhat in bad times.
If incoming electrons were affected by the Earth's magnetic field, Foster reasoned, the South Atlantic Anomaly would act like a "hole in the path of their motion," allowing them to fall deeper into the Earth's atmosphere.
Mental health services are failing to adequately support students when they leave home and move to university, allowing them to fall through the gaps at a time of increased vulnerability and stressful new pressures, according to research.
Generally, the diesel generation parks are not providing power to the grid but offering it to other businesses or organisations, allowing them to fall into the category of "demand-side response" at peak moments.
