English grammar rule These singular noun

This, that, these, and those are referred to as “demonstratives,” and they go in pairs. This and that are singular, while these and those are plural. If your noun is plural, use a plural demonstrative. For singular nouns, use a singular demonstrative. Collective and uncountable nouns are considered singular.

Examples of 'These singular noun' rule

Incorrect	These book will be written in English.
Correct	This book will be written in English.
Correct	These books will be written in English.
Incorrect	These supply came from the store.
Correct	This supply came from the store.