Questions & Answers about Tavan çok yüksek.
In Turkish, the verb to be (olmak) is usually omitted in simple present tense. The sentence literally reads Ceiling very high, and the “is” is understood implicitly. If you wanted to add it explicitly (more formally), you could use the copula suffix -dir:
Tavan çok yüksektir.
Here yüksek is functioning as a predicate adjective (describing the subject). In Turkish, predicate adjectives and predicate nouns follow the subject (and any adverbs). If you want to use yüksek attributively (directly modifying the noun), it precedes the noun:
yüksek tavan → “high ceiling” (noun phrase)