Are "parsley, avocado and cucumber" uncountable nouns?
Answer from a Native speaker
"Parsley" is an uncountable noun, but "avocado" and "cucumber" are both countable. Ex: He bought three avocados. Ex: How many cucumbers do we have in the refrigerator? Sometimes nouns that are countable are used in the singular and seem like they may be uncountable. Ex: This recipe calls for egg and avocado. In the example above, both "egg" and "avocado" are countable nouns, however, they are used as singular nouns to express their general form which can make them appear as though they are uncountable. This is common to use nouns in the singular form when referring to them generally.