【明報專訊】Some terms involve two or more nouns (or adjectives and nouns) in a row to form a single phrase that is considered a single unit. Most of these compounds have a generic, uncountable meaning rather than detailing an actual situation. The initial word acts like an adjective (even though it may be a noun) and modifies the other word(s). But when the first word is a noun as in these next examples, the temptation is to use the plural form or possession.