Learn Hardcore Turkish: Enflasyon yüksek.

In Turkish, the present‐tense copula (“to be”) is normally omitted in simple affirmative sentences, especially in spoken or informal contexts. The adjective yüksek directly follows the noun enflasyon to express “Inflation is high,” even though there’s no explicit is.

What case is enflasyon in, and why doesn’t it have a suffix?

Enflasyon is in the nominative case, which is the default form for a sentence’s subject in Turkish. The nominative usually has no suffix. If you added an accusative suffix (-u/-ü), for example enflasyonu, you would be making it a direct object instead.

Why does the adjective come after the noun, when in English we say “high inflation”?

There are two different constructions:

As a noun phrase (attributive adjective), you say yüksek enflasyon = “high inflation.”
As a predicate sentence, you follow the pattern Subject + Predicate (adjective), so you say Enflasyon yüksek = “Inflation is high.”

How can I make the sentence more formal or written by adding a copula?

Attach the formal copular suffix -dir (for general truths or written style) to the adjective. Because of consonant harmony it becomes Enflasyon yüksektir, literally “Inflation is high.”