The phrase "allow him to understand" is correct and usable in written English.
You can use it when you want to express the idea of giving someone the opportunity or means to comprehend something.
Example: "The teacher used various methods to allow him to understand the complex topic better."
Alternatives: "enable him to grasp" or "help him comprehend".
The glaciers may already be melting, but knowing their precise state will, he hopes, allow him to understand what it will take to save them.
His sheer dignity in grief seems both to allow him to understand that he will die, and to allow him to be frightened.
At the same time, it is absolutely my duty to ensure that I instill in him the knowledge and values that will allow him to understand why rape is never an option.
He's broken, and he's also smart enough to realize — and Mr. Lonergan is wise and generous enough to allow him to understand — that nothing will make him whole again.
Dick DeGuerin, another well-known Houston defense lawyer who has represented clients across the courtroom from Mr. Hardin, says the prosecutor-turned-defense lawyer has a perspective that will allow him to understand both sides in the Anderson court of inquiry.
The actor should be well-versed in acting techniques which allow him to understand and assimilate in detail the diverse and subtle changes of the character's ideas and emotions in relation to a particular situation or event, so that the moment he goes on camera, he is quite naturally drawn deep into the world of the character's life.
But the president — who was not wearing an earpiece that would have allowed him to understand Mr. Gentiloni's challenge, issued in Italian — quickly contradicted his guest.
As the rock icon sang, it became clear that the show allowed him to understand not only himself but what goes into the making of a self.
"His understanding of the nature of the threat that we face, the evolving nature of it and the creativity these terrorist groups bring to the effort, allows him to understand what we need to do to guard against it".
However accurate John's picture of his grandmother's history, it allows him to understand his mother more completely — how her separation from her own mother will have affected her and, in turn, him.
This allowed him to understand that modernity was not something passed, nor necessarily a break with tradition, but a need for adaptation to the fast times that were to come.
