How to tell an abstractive word countable or uncountable?
The simple answer is that you cannot tell. English has been created from many, many other languages…..pre-Roman Celtic, Old Norse, Saxon, Latin, Ancient Greek,Norman French and tens more languages over the centuries. Consequently its spelling does not follow convenient and easy-to- learn rules. Even where rules exist there are many exceptions. This applies to pluralisation too. Whether concrete or abstract, words may or may not have a definite plural. You can, of course, count sheep….but there may be one sheep or twenty sheep. Pluralisation is spelling is less common in abstract nouns than in concrete, however. It is best to check and learn the pluralisation of each abstract noun as you come across it rather than to seek any ‘countable’ basis (or logical reason) for its pluralisation.