This and that are demonstrative adjectives used with a singular noun. Use this for one person, one thing, or one idea that is close, immediate, or being introduced. Use that for one person, one thing, or one idea that is farther away or less immediate. The noun stays singular: this book, that chair, this water, that information. With uncountable nouns, the demonstrative still looks singular because the noun has no plural form. Compare this rice with that music. The demonstrative appears directly before the noun, so this and that do not stand alone here; they describe which singular thing you mean.

These and those are demonstrative adjectives used with plural countable nouns. Use these for more than one nearby person or thing, and those for more than one person or thing farther away or less immediate. The noun must be plural: these shoes, those books, these people, those houses. The form changes with number, so this becomes these and that becomes those when the noun is plural. The demonstrative comes before the noun and shows which group you are talking about. These apples points to one set of apples; those apples points to another set, usually at a distance or outside the speaker’s immediate focus.

Plural demonstrative adjective use

Example	Pattern
These books are on my desk.	Use these with plural countable nouns that are near or immediate.
Those shoes are by the door.	Use those with plural countable nouns that are farther away or less immediate.

This and these point to what is near the speaker, near the listener, or part of the immediate situation. That and those point to what is farther away, already separated from the speaker, or less immediate in the conversation. The difference is not only physical distance. A phone on the table can be this phone if it is being held up or discussed closely, while a phone across the room can be that phone. In conversation, this often feels close in time or attention, while that feels more distant. The same contrast appears with people, objects, sounds, and ideas: this song for the one playing now, that song for another song not as immediate; these seats for the ones here, those seats for the ones over there.

Distance meaning in demonstratives

Usage	Explanation	Example
Near speaker	Use this and these for people or things close to you or part of the current situation.	This chair is next to me.
Far from speaker	Use that and those for people or things farther away from you.	That tree is across the street.

Demonstrative adjectives always come before the noun they describe. The pattern is demonstrative + noun: this car, that answer, these flowers, those shoes. They do not follow the noun in normal English. When another word comes with the noun, the demonstrative still stays first: this old house, those three students, that red umbrella. Demonstratives also appear in fixed phrases such as this kind of problem and that kind of behavior. In these phrases, the demonstrative still comes first, then the phrase that identifies the type. The demonstrative points to the category, and the noun in the phrase names the type or idea.

Demonstratives before noun phrases

Usage	Explanation	Example
Before a noun	Use demonstrative adjectives before a noun to point to a specific person or thing.	This answer is correct.
With kind phrases	Use this kind of and that kind of before a noun to describe a type or category.	I like this kind of music.

Demonstratives can point to time, events, news, and shared topics, not only to physical objects. This can refer to the present moment or a very recent time: this morning, this week, this year. That can refer to a later or more distant time: that day, that evening, that period. These and those can also talk about time periods: these days for the present time, those days for a past time that feels separate. In conversation, demonstratives often introduce or refer back to a topic: this idea, that story, these problems, those questions. The word points to the topic being discussed and helps organize the conversation around it.

Non physical demonstrative uses

Usage	Explanation	Example
Talking about time	Use this and these for the present time, and that and those for a more distant time.	These days are very busy.
Introducing a topic	Use this or that to refer to an idea, news item, or topic in conversation.	That is an interesting idea.

Some demonstratives appear in fixed expressions. This one and that one replace a singular noun that is already understood: I like this one more than that one. These ones and those ones can appear in some varieties of English, but standard English usually uses these and those alone with plural nouns, so these books is more natural than these ones in most cases. These days means the present time in general, and those days means a past time period. Demonstrative adjectives and demonstrative pronouns use the same forms, but they work differently. A demonstrative adjective comes before a noun: this car. A demonstrative pronoun stands alone and replaces the noun: This is mine or That was expensive. In this car, this describes the noun car; in This is mine, this is the whole noun phrase.