What are the rules for using demonstrative pronouns in grammar syntax?

The rules for using demonstrative pronouns in grammar syntax are as follows:

1. Agreement with the noun: Demonstrative pronouns must agree in number and gender with the noun they are referring to. For example, "this" is used for singular nouns close to the speaker, while "these" is used for plural nouns close to the speaker.

2. Distance from the speaker: Demonstrative pronouns indicate the proximity of the noun to the speaker. "This" and "these" are used for objects or people that are close to the speaker, while "that" and "those" are used for objects or people that are farther away.

3. Specificity: Demonstrative pronouns can be used to point out specific objects or people. For example, "this" and "that" are used to refer to singular nouns, while "these" and "those" are used to refer to plural nouns.

4. Context: The choice of demonstrative pronouns can also depend on the context of the sentence. For example, if there are multiple objects or people close to the speaker, "this" can be used to refer to the one that was mentioned first or is more important.

5. Avoid ambiguity: It is important to use demonstrative pronouns clearly to avoid confusion. Using specific nouns or adding additional information can help clarify the intended meaning.

Overall, the rules for using demonstrative pronouns involve agreement with the noun, indicating proximity, specificity, considering the context, and avoiding ambiguity.