because in one case we are thinking of the crowd and in the other of the persons who compose the crowd. So in speaking of a committee, we may say
The Committee thinks that a certain thing should be done.
The Committee think that a certain thing should be done.
The first phrase would indicate that the committee had considered and acted on the subject and the statement represented a formal decision. The second phrase would indicate the individual opinions of the members of the committee which might be in agreement but had not been expressed in formal action. In doubtful cases it is safer to use the plural.
Entire accuracy in these cases is not altogether easy. As in the case with all the nice points of usage it requires practice and continual self-observation. By these means a sort of language sense is developed which makes the use of the right word instinctive. It is somewhat analogous to that sense which will enable an experienced bank teller to throw out a counterfeit bill instinctively when running over a large pile of currency even though he may be at some pains to prove its badness when challenged to show the reason for its rejection.
The young student should not permit himself to be discouraged by the apparent difficulty of the task of forming the habit of correct speech. It is habit and rapidly becomes easier after the first efforts.
The relation of a noun to a verb, to another noun, or to a preposition is called its case. There are three cases called the nominative, objective, and possessive. When the noun does something it is in the nominative case and is called the subject of the verb.
When the noun has something done to it it is in the objective case and is called the object of the verb.
When a noun depends on a preposition, it is also in the objective case and is called the object of the preposition.
The preposition on which a noun depends is often omitted when not needed for clearness.
He was ten minutes late (late by ten minutes).
He is 18 years old (old by or to the extent of 18 years).
The nominative and objective cases of nouns do not differ in form. They are distinguished by their positions in the sentence and their relations to other words.
When one noun owns another the one owning is in the possessive case.