If you want to treat the boy with homeopathy, you have to take him to a practitioner. You don't have to draw attention to the stammer itself, as the homeopathic remedy won't be given for the stammer alone anyway! You will need a constitutional remedy for this case, so it will only be one thing among many considered for the remedy you'll give.

A practitioner would need to take the case in person and gather a lot more information than the very little you've given here, anyway, so there's really no point in giving you a list of remedies "for stammering" to try out.

Take him to a practitioner. It'll be the best thing you could for him--what ever the cause of this problem (be it teachers, or school situations, or physiological development difficulties...all will be resolved with the remedy anyway).

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...and deliverance has many faces<br />but grace<br />is an aquaintance of mine