Learn Hardcore Turkish: Hamur yumuşak.

In Turkish, the present-tense copula (is/am/are) is normally dropped in descriptive sentences. You simply state the subject and the adjective together. Thus Hamur yumuşak literally conveys the dough is soft without needing a separate verb.

Why doesn't hamur have an article like the or a?

Turkish has no direct equivalents of the or a. Definiteness is inferred from context. If you want to specify a dough you can say bir hamur, and for this dough you can say bu hamur.

What case is hamur in, and why doesn’t it take any suffix?

Here hamur is the subject (nominative case), which in Turkish carries a zero ending in simple statements. Only objects or other roles get visible case suffixes.

Could I say yumuşak hamur instead of Hamur yumuşak?

Yumuşak hamur is a noun phrase meaning soft dough, not a full sentence. To state the dough is soft, you use Hamur yumuşak (subject + predicate adjective).

Why doesn’t yumuşak have any tense or agreement suffix?

In present-tense descriptive (adjectival) sentences, adjectives remain unsuffixed. If you want to make a general or emphatic statement, you can add the copular suffix -dır:
Hamur yumuşaktır – “Dough is generally soft” or “The dough is indeed soft.”

How do you form a question like Is the dough soft? in Turkish?

Attach the question particle mı/mi/mu/mü after the adjective, following vowel harmony:
Hamur yumuşak mı?

How do you negate Hamur yumuşak to say The dough is not soft?

Use the negator değil after the adjective:
Hamur yumuşak değil.

How do you say my dough is soft?

Add the first-person possessive suffix -um to hamur:
Hamurum yumuşak.

How can I specify this dough or that dough?

Use demonstratives before hamur:
Bu hamur yumuşak – “This dough is soft”
O hamur yumuşak – “That dough is soft.”

Why isn’t hamur plural in Hamur yumuşak?

When talking about an uncountable substance like dough in general, Turkish keeps it singular. The plural hamurlar would refer to multiple individual doughs or batches.