Learn Hardcore Ukrainian: Озеро було спокійним і прозорим усе літо.

In Ukrainian, when a predicate adjective follows a form of the verb “бути” (to be)—especially in the past or future tenses—it is typically put in the instrumental case. This case shows the state or condition of the subject, so here “спокійним” (calm) and “прозорим” (clear) describe the lake’s condition.

What is the role of the verb “було” in this sentence?

“було” is the past tense form of the verb “бути” (to be). It acts as a linking verb that connects the subject “Озеро” (Lake) with its descriptive predicate adjectives “спокійним” and “прозорим,” indicating that the lake had those qualities during the period mentioned.

How do the subject “Озеро” and the predicate adjectives agree in this sentence?

The noun “Озеро” is neuter singular, and because it is the subject, the linking verb “було” takes the neuter singular form. Likewise, the predicate adjectives “спокійним” and “прозорим” appear in the neuter singular instrumental form to agree with “Озеро.”

What does the phrase “усе літо” mean, and why is “усе” used?

“усе літо” translates to “all summer.” The word “усе” is the neuter singular form of the adjective “весь” (meaning “all” or “entire”), which agrees with “літо” (summer), a neuter singular noun. This phrase serves as a time expression, indicating the entire summer period during which the described state applied.

Would it be possible to use the adjectives in the nominative case instead of the instrumental in this sentence?

While adjectives in Ukrainian can appear in the nominative case in many contexts, when they serve as predicate adjectives following a past or future form of “бути,” using the instrumental case is the standard grammatical construction. Using the nominative here would sound ungrammatical and would change the intended expression of the lake's temporary state.