Is there any explanation regarding why some nouns are used in singular form while the others are used in plural form such as price tags in stores or menus in restaurants. I know that in languages where there is count/mass distinction uncountable nouns such as milk, meat etc. are tagged in singular form. For example in Swedish, at the stores many countable items are naturally tagged in plural form such as "apelsiner(oranges)"and "jackor(jackets)" as they are tagged in English. However I noticed out that countable products such as cucumbers and onions are tagged in singular form as "gurka" and "lök" rather than "gurkor" and "lökar" on the contrary to other fruits and vegetables. Is there any examination/explanation in linguistics directly referring such terminology?