Learn Hardcore Turkish: Yeni öğretmen çok dakik; derse tam saatinde giriyor. - The new teacher is very punctual; she enters the class exactly on time.

Yeni öğretmen can mean “the new teacher” if the person is specific/known.
To say “a new teacher,” add bir: Yeni bir öğretmen.
As a topic sentence about someone already known in context, Yeni öğretmen ≈ “The new teacher.”

What does dakik mean, and is it related to dakika?

dakik = punctual (as an adjective about people or behavior).
It’s not the same as dakika (minute). They’re related etymologically but different words.
Synonyms/near-synonyms: zamanında, vaktinde, tam saatinde, dakik biri (a punctual person).

How is çok used here? Could I say çok fazla dakik or gayet dakik?

With adjectives, çok = “very”: çok dakik = very punctual.
çok fazla usually modifies quantity, not adjectives; avoid çok fazla dakik.
Alternatives: gayet/oldukça/pek (colloquial) dakik.

Why is it derse? Does girmek take the dative?

Yes. girmek “to enter” selects the dative -(y)e/a:

okula/sınıfa/derse/sınava girmek (enter school/class/lesson; take an exam).
Not accusative: say derse girmek, not dersi girmek.

Could I say dersine giriyor instead of derse giriyor?

derse giriyor: enters (goes to) the lesson in general.
X’in dersine giriyor: attends X’s class (possessive makes it “someone’s lesson”).
For a teacher entering their own class you can say kendi dersine giriyor, but the neutral, idiomatic choice is simply derse giriyor.

What exactly is tam saatinde? Why the possessive + locative? Why not tam saatte?

tam saatinde literally “exactly at its hour/time” = “exactly on time.”
- Morphology: saat-i-nde (saat + 3sg possessive -i + locative -nde).
The possessive marks the scheduled/appropriate time of the event.
tam saatte is not the idiomatic way to mean “on time.” Use saatinde/zamanında/vaktinde.
For a clock time, say tam dokuzda (= exactly at nine).

Is saatinde implicitly “at the class’s scheduled time”? Should I say dersin saatinde?

Yes, saatinde is understood from context as “at its scheduled time.” You can make it explicit with dersin saatinde, but it’s usually unnecessary unless contrast/clarity is needed.

Why a semicolon here? Could I use a comma or a period?

The semicolon links two closely related independent clauses without a conjunction.
A period is also fine: Yeni öğretmen çok dakik. Derse tam saatinde giriyor.
A comma is common in informal writing, though purists prefer period/semicolon here.

Why giriyor (present continuous) instead of girer (aorist) for a habitual statement?

girer (aorist) states a timeless habit/rule: …derse tam saatinde girer.
giriyor can also describe a current, characteristic pattern but sounds more like ongoing behavior being observed now.
Both are correct; choose:
- General rule: girer
- Current/observed tendency: giriyor

Where is the subject pronoun? How do we know it’s “he/she”?

Turkish is pro‑drop. The verb ending shows person/number. giriyor is 3rd person singular, so context supplies o (he/she). You can add O for emphasis/contrast, but it’s normally omitted.

How would this look with a plural subject?

Yeni öğretmenler çok dakik; derse tam saatinde giriyorlar.
In 3rd‑person plural with an explicit plural subject, -lar on the verb is optional in many contexts: giriyor(lar). Adding -lar is more explicit/natural with human subjects.

Can I change the word order, e.g., move tam saatinde?

Yes, adverbials can move for emphasis:

Tam saatinde derse giriyor.
Derse tam saatinde giriyor. (original order) Keep the finite verb last in neutral order.

How do I negate or ask a question with these parts?

Negation: Yeni öğretmen çok dakik değil; derse tam saatinde girmiyor.
Yes/no question:
- Yeni öğretmen çok dakik mi; derse tam saatinde giriyor mu?
- The question particle mi/mı/mü/mu is written separately and follows vowel harmony.

Any pronunciation tips for yeni öğretmen çok dakik; derse tam saatinde giriyor?

ğ in öğretmen lengthens the preceding vowel; it’s not a hard “g.”
ö is a front rounded vowel (like German ö).
ç = “ch.”
giriyor has fixed -yor; stress in Turkish is usually on the last syllable: öğ-ret-MEN, da-KİK, gi-ri-YOR.

How do I say “exactly at nine” vs “on time”?

Exactly at nine: tam dokuzda.
On time: saatinde / zamanında / vaktinde.
Example: Derse tam dokuzda giriyor (he/she enters exactly at nine).

What’s going on morphologically with derse and saatinde?

derse = ders + e (dative; last vowel is front, so use -e).
saatinde = saat + i + nde (3sg possessive + locative; buffer n because the possessive ends in a vowel; -de not -te because it follows a vowel).

Could I replace derse with sınıfa or okula? What changes?

Yes, each targets a different noun:

sınıfa giriyor: enters the classroom (the room).
derse giriyor: goes into/starts the lesson (the activity).
okula giriyor: enters the school (the building/campus).