Learn Hardcore Russian: Это полезное слово.

Это is a demonstrative pronoun that serves to introduce or identify the subject. In this context, it implies "this is" (or "it is") without using an explicit copula, which is common in Russian.

Why does the adjective полезное end with -ое?

Russian adjectives must agree with the noun they modify in gender, number, and case. The noun слово is neuter, singular, and in the nominative case, so the adjective takes the neuter singular nominative ending -ое to match it correctly.

What is the typical word order in a phrase like полезное слово in Russian?

In Russian, adjectives typically come before the noun they modify. In this sentence, полезное precedes слово, which is the standard order, directly translating to "useful word" in English.

Why is there no explicit verb equivalent to "is" in this sentence?

In Russian, the present tense form of the verb быть (to be) is usually omitted. Therefore, "Это полезное слово" conveys "This is a useful word" without needing to include a separate word for "is".

How do gender and case influence the agreement between полезное and слово?

Since слово is a neuter noun in the nominative singular, any adjective describing it must also be in the neuter nominative singular form. This requirement ensures that полезное agrees with слово in gender, number, and case, which is a key rule in Russian grammar.