Learn Hardcore Turkish: Hemen hemen bütün daireler doluymuş. - Almost all the apartments are apparently full.

-miş/-mış/-muş/-müş here is the evidential (reported/inferential) past on a nominal predicate. It signals that the speaker learned the information indirectly or is inferring it.
So doluymuş ≈ “apparently/it seems (they) were full.”
Contrast:
- doluydu = “were full” (witnessed, plain past).
- doluymuş = “were apparently full / were said to be full” (hearsay/inference/softening).

Why is there a y in doluymuş, and why is it -muş (not -miş)?

The form is: dolu + y + muş.
y is a buffer consonant inserted between the vowel-final adjective dolu and the suffix to prevent two vowels from clashing.
The vowel in the suffix follows vowel harmony: since the last vowel of dolu is u (a back, rounded vowel), the harmonizing variant is -muş.

Could I say daireler dolmuş instead of doluymuş?

Yes, but it changes the focus:
- doluymuş uses the adjective dolu “full/occupied,” describing a state: “were apparently full.”
- dolmuş uses the intransitive verb dol- “to fill (up),” implying a change of state/result: “apparently (they) have filled up/became full.”
Also note: dolmuş is a common noun meaning “shared minibus,” unrelated here.

Why isn’t it dolular to match the plural subject?

Predicative adjectives in Turkish don’t take plural: Daireler dolu. (not “dolular”) = “The apartments are full.”
dolular is possible only when the adjective is turned into a noun meaning “the full ones,” typically in contrast: Boş olan az; dolular çok.

Shouldn’t it be doluymuşlar since daireler is plural?

With nominal predicates, 3rd person plural agreement on the copula is optional and most natural with human subjects.
For inanimate plurals like daireler, the unmarked and most natural form is singular agreement: doluymuş.
doluymuşlar is grammatically possible but tends to sound marked/odd with inanimates unless you’re emphasizing a human group.

What exactly does hemen hemen mean? Is it just “immediately” repeated?

hemen hemen is a fixed expression meaning “almost” or “nearly,” not “immediately.”
Examples: hemen hemen herkes “almost everyone,” hemen hemen hiç “hardly any.”
It often modifies quantifiers like bütün, her, hepsi.

Can I use neredeyse instead of hemen hemen?

Yes: Neredeyse bütün daireler doluymuş ≈ “Almost all the apartments were apparently full.”
Nuance: neredeyse is slightly more colloquial and also freely modifies verbs/adjectives (e.g., neredeyse düşüyordum “I almost fell”); hemen hemen is especially common before quantifiers.

Does hemen hemen modify bütün or dolu here? What if I move it?

In Hemen hemen bütün daireler doluymuş, it modifies bütün: “Almost all apartments are (apparently) full.”
If you say Bütün daireler hemen hemen doluymuş or Daireler hemen hemen doluymuş, it means “All/The apartments are almost full” (degree of fullness), not “almost all of them.” That’s a different meaning.

What’s the difference between bütün, tüm, and hepsi?

bütün and tüm both mean “all/entire,” used before a noun: bütün/tüm daireler.
hepsi is a pronoun: dairelerin hepsi = “all of the apartments.”
Style: tüm can feel a bit more formal/concise; meaning is essentially the same as bütün here.

Could I say Hemen hemen her daire doluymuş? Is that the same?

Hemen hemen her daire doluymuş = “Almost every apartment was apparently full.”
It’s very close in meaning to “almost all,” but:
- hemen hemen her suggests a distribution over individual items.
- hemen hemen bütün suggests a near-totality of the set as a whole.

Why is daireler in the bare form (no case ending)?

It’s the subject of a nominal sentence. Subjects appear in the nominative (bare) form: [Subject] [Predicate].
The predicate is the adjective dolu with the evidential past: dolu + y + muş.

How do I make this negative or a yes/no question?

Negative (reported): Hemen hemen bütün daireler dolu değilmiş. (“apparently they weren’t full.”)
Yes/no question (reported): Hemen hemen bütün daireler doluymuş mu?
Note the question particle mi/mı/mü/mu comes after the whole predicate and is written separately.

What are the closest plain-past and present-tense equivalents?

Witnessed past: Hemen hemen bütün daireler doluydu. (“Almost all apartments were full.”)
Present (plain statement): Hemen hemen bütün daireler dolu. (“Almost all apartments are full.”)
Reported present/past blended nuance is what doluymuş gives you.

Does dolu here mean “physically full” or “occupied”?

With real estate units like daire(ler), dolu commonly means “occupied” (no vacancy).
Context can also allow the literal “full” reading (e.g., a container), but with apartments the idiomatic reading is “occupied.”

Does daire always mean “apartment”?

No. daire can mean “apartment/flat,” “office/unit,” “department (in an institution),” or “circle (geometry).”
In everyday housing context, it’s “apartment.” Context decides the sense.