The phrase 'let him cross' is correct and usable in written English.
For example, you could use it in a sentence like, "The guard let him cross the bridge."
They let him cross the battle lines every day to get to work.
As an 11-year-old living in London, he had persuaded his parents to let him cross the Atlantic alone and move in with an uncle in Connecticut.
Ahmad, a man from Idlib, a Syrian city which has been ravaged during the civil war, spoke to The Independent after he had implored Hungarian border guards to let him cross the border.
"And in fact one of the policemen outside let him cross the barrier and come up to the window and there was a ventilation grill, and we were actually able to speak through that, but not a proper farewell".
Don't let him cross the line between flirt and sexual harassment.
The son had struck up a relationship of sorts with the guards, giving them things in return for letting him cross back and forth.
Performing both simultaneously lets him cross great distances by doing a dash-jump.
As scary as it is, if you want your child to become an adult, you're going to have to let him or her learn to cross streets, get lost and fight giants on his or her own.
Keep him on hold, keep his legs crossed, and let him hide his stuff here, hide his stuff there, but if he's doing that he's not giving us any more problems, and it gives us a chance to restore our integrity in that part of the world.
On loan from West Brom, Camp turned provider when he threw the ball out to Lewis Grabban, who scampered down the right and crossed but Pitman volleyed wide, while Marc Pugh's control let him down from another Grabban cross.
I find it helpful to tell him I'm getting cross, to let him know the effect his behaviour is having on me.
