Most collective nouns encountered in everyday speech, such as "group," are mundane and are not specific to one kind of constituent object. For example, the terms "group of people," "group of dogs," and "group of ideas" are all correct uses. Others, especially words belonging to the large subset of collective nouns known as terms of venery (words for groups of animals), are specific to one kind of constituent object. For example, "pride" as a term of venery refers to lions— but not to dogs or llamas.
Derivation accounts for many collective words. Because derivation is a slower and less productive word formation process than the more overtly syntactical morphological methods, there are fewer collectives formed this way. As with all derived words, derivational collectives often differ semantically from the original words, acquiring new connotations and even new denotations.
The English endings -age and -ade often signify a collective. Sometimes the relationship is easily recognizable: baggage, drainage, blockade. However, even though the etymology is plain to see, the derived words take on quite a special meaning.
German uses the prefix Ge- to create collectives. The root word often undergoes umlaut and suffixation as well as receiving the Ge- prefix. Nearly all nouns created in this way are of neuter gender. Examples include:
Two good examples of collective nouns are "team" and "government," which are both words referring to groups of (usually) people. Both "team" and "government" are count nouns. (Consider: "one team," "two teams," "most teams"; "one government," "two governments," "many governments"). However, confusion often stems from the fact that plural verb forms can often be used with the singular forms of these count nouns (for example: "The team have finished the project"). Conversely, singular verb forms can often be used with nouns ending in "-s" that were once considered plural (for example: "Physics is my favorite academic subject"). This apparent "number mismatch" is actually a quite natural and logical feature of human language, and its mechanism is a subtle metonymic shift in the thoughts underlying the words.
In British English, it is generally accepted that collective nouns can take either singular or plural verb forms depending on the context and the metonymic shift that it implies. For example, "the team is in the dressing room" (formal agreement) refers to the team as an ensemble, whilst "the team are fighting among themselves" (notional agreement) refers to the team as individuals. More strikingly, this is also British English practice with names of countries and cities in sports contexts; for example, "Germany have won the competition," "Madrid have lost three consecutive matches," etc. In American English, collective nouns usually take singular verb forms (formal agreement). In cases where a metonymic shift would be otherwise revealed nearby, the whole sentence may be recast to avoid the metonymy. (For example, "the team are fighting among themselves" may become "the team members are fighting among themselves" or "the team is fighting [period].") See American and British English differences - Formal and notional agreement.
A good example of such a metonymic shift in the singular-to-plural direction (designated by the Latin term plurale tantum) is the following sentence: "The team have finished the project." In that sentence, the underlying thought is of the individual members of the team working together to finish the project. Their accomplishment is collective, and the emphasis is not on their individual identities, yet they are at the same time still discrete individuals; the word choice "team have" manages to convey both their collective and discrete identities simultaneously. A good example of such a metonymic shift in the plural-to-singular direction is the following sentence: "Mathematics is my favorite academic subject." The word "mathematics" may have originally been plural in concept, referring to mathematic endeavors, but metonymic shift—that is, the shift in concept from "the endeavors" to "the whole set of endeavors"—produced the usage of "mathematics" as a singular entity taking singular verb forms. (A true mass-noun sense of "mathematics" followed naturally.)
There is often confusion about, and confounding of, the two different concepts of collective noun and mass noun. Generally, collective nouns are not mass (non-count) nouns, but rather are a special subset of count nouns. However, the term "collective noun" is often used to mean "mass noun" (even in some dictionaries), because users confound two different kinds of verb number invariability: (a) that seen with mass nouns such as "water" or "furniture," with which only singular verb forms are used because the constituent matter is grammatically nondiscrete (although it may ["water"] or may not ["furniture"] be etically nondiscrete); and (b) that seen with collective nouns, which is the result of the metonymical shift, discussed earlier, between the group and its (both grammatically and etically) discrete constituents.
Some words, including "mathematics" and "physics," have developed true mass-noun senses despite having grown from count-noun roots.
The terms are often conflated and the Chicago Manual of Style insists that distinguishing them is for "sticklers".
Sometimes a term of venery will apply to a group only in a certain context. "Herd" can properly refer to a group of wild horses, but not to a group of domestic horses. A "paddling of ducks" only refers to ducks on water. A group of geese on the ground are referred to as a "gaggle of geese" while a "skein of geese" would refer to them in flight.
Interest in constituent-object-specific collective nouns has always remained high, and the coining of candidate collective nouns has been a pastime (usually humorous) of many writers ever since, including for non-animal nouns, such as professions, e.g., a "sequitur of logicians."