Depends on your region and the name in question. e.g. macquarie (https://www.macquariedictionary.com.au/resources/view/resource/6/ https://www.macquariedictiona

Depends on your region and the name in question. e.g. macquarie (https://www.macquariedictionary.com.au/resources/view/resource/6/ https://www.macquariedictionary.com.au/resources/view/resour...) say: > Personal names ending in s are these days often given the regular apostrophe s, whatever their number of syllables or their sound: > > Burns's poetry > Dickens's novels > > Those who have occasion to refer to classical or biblical names of several syllables may still prefer the apostrophe alone, as with: > > Jesus' teachings > Moses' law > Euripides' plays