how can we use study for the third person singular
The singular demonstrative pronouns are this and that.The plural demonstrative pronouns are these and those.
he wrote a book of studies
Georgius Agricola wrote a book of studies to further the study of geology.
Georgius Agricola wrote a book of studies to further the study of geology.
"Book" can be both singular and plural. When referring to one book, it is singular. When referring to more than one book, it is plural.
Georgius Agricola wrote a book of studies to further the study of geology.
A singular noun or a singular noun phrase usually follows "this" or "that." For example, "this book" or "that car."
Two singular objects added together are plural, so, the book and pen are in the desk.
noun that are plural in form but singular in meaning
The word "person's" is a singular possessive form. It indicates ownership or association with a single person. For example, in the sentence "This is John's book," "John's" is the singular possessive form indicating that the book belongs to John. If you were referring to the possessive form for multiple people, the correct form would be "people's." For example, "This is the people's choice."
Book’s
A singular possessive noun shows ownership or relationship to one person or thing. It is formed by adding an apostrophe followed by the letter "s" ('s) to the singular noun. For example, "the dog's bone" or "Sara's book."