From the description is this a division 2/3 local league level?
Stand back a bit from the service line when serving. Try 10-12inches back. Add a little speed to the shuttle in the serve if he’s able to do that so that’s it’s longer. This will increase percentages him getting it over. The return of serve will be longer and thus more shuttles will come to you for the third shot.
Is he getting his racquet up at the net after serving?
Generally people stand a bit too close to the front service line if they are in a rally in the forecourt making it seem everything is going really fast. Take a step backwards after the third shot.
He doesn’t really have to place the shuttle on court if he’s at the front. It’s ok for the rally to continue. The important thing to concentrate on taking the shuttle higher so that the shuttle goes downwards. It’s ok not to kill if a bit unsure but make the shuttle go downwards. Once he’s got the hang of that, then add if it’s a soft downwards shot, try to play it a bit more to the centre.