Collective nouns, such as police, people, cattle, livestock, etc. Usually used as the plural, always means the plural. When used as a subject, its predicate should be plural.
But there are countless collective noun such as clothes, poems, luggage, furniture, machinery, scenery, jewelry and so on. , used only in the singular, is usually used as an uncountable noun in collective noun, indicating the singular meaning. When used as the subject, the predicate verb is in the singular form.