This post is dedicated to Clive Upton, who was surprised that I spelled Granddad with two d’s in the middle. I’m no native speaker, and just told myself: surely it must be grand + dad. Since then I looked it up in my copy of the Concise Oxford Dictionary, which allows for either: grand(d)ad, but this doesn’t help the linguistically insecure or those of us who just want to know which of the two is the correct spelling. Surely one must be better than the other? So, tell us what YOU think is better or more correct? Or if you think either is fine, in which case it wouldn’t be a usage problem?
Even if most people on this blog voted for granDDad (71.4% at the moment of writing), Penguin seems to prefer granDad. Or seemed to do so in the mid-1980s: I’ve just reread Nice Work by David Lodge (p. 373, where Grandad is spelled with a capital G as well).