Why is it not correct to translate this as "He may."? I thought poder could mean "can" or "may".
'Able to' is more like a phrase that you say--it's something like how it's obligatory that you have to follow 'neither' with 'nor' later on in the sentence. But it's probably because 'He is able' has a different meaning; because 'able' means that [one] is capable and fit. I'm somewhat pf a native speaker, and I can say 'puede/o' isn't used that way XD 'Able to' is the closest english equivalent to 'puede' in spanish.