Two sentences:
(1) She has great experience in her work.
(2) ‘She spoke with a great enthusiasm about the new plans.
Question: Why is there no article ‘a’ with ‘great experience’ in the first sentence and one with ‘great enthusiasm’ in the second sentence? In my mind ‘experience’ and ‘enthusiasm’ are both uncountable nouns and therefore we can’t use the indefinite article ‘a’ with ‘great experience’ and ‘great enthusiasm’. I guess I am wrong. Could you explain why?