Learn Hardcore Turkish: Aniden esnedim; uyumayı ertelememek lazım. - I yawned suddenly; we shouldn’t postpone sleeping.

Aniden esnedim (most natural: adverb before the verb).
Ben aniden esnedim (adds an explicit subject for emphasis).
Esnedim aniden (possible for emphasis, but less neutral). Synonyms: birden, birdenbire, ansızın (register varies slightly: ansızın is a bit literary).

Why isn’t there a subject pronoun like ben before esnedim?

Turkish verbs show the subject in their endings. Esnedim already means I yawned; the suffix -dim marks first-person singular past. You add ben only for emphasis or contrast.

How is esnedim formed, and how would I change the tense or make it negative?

Root: esne- (to yawn)
Past tense: -di
1st singular: -m So: esne-di-m → esnedim.
Other forms:
Negative: esnemedim (I didn’t yawn)
Present continuous: esniyorum (I am yawning)
Aorist (habit): esnerim (I yawn, habitually)

Does esnemek only mean “to yawn”?

Its primary everyday meaning is to yawn. In technical/physics contexts it can mean “to stretch/elongate” (e.g., a spring), but for “to stretch (your body)” you’d usually say gerinmek.

Why is there a semicolon between the clauses? Could I use a period or a comma?

Turkish uses the semicolon much like English to link two closely related independent clauses: Aniden esnedim; uyumayı ertelememek lazım.

A period is also fine: two separate sentences.
A comma alone is not ideal between two full independent clauses; use a conjunction (e.g., çünkü, ama) or a semicolon.

What does lazım mean here, and how does this construction work?

Lazım means necessary/needed. A common pattern is: verbal noun in -mak/-mek + lazım.
Examples:

Uyumak lazım = It’s necessary to sleep.
In your sentence, the whole idea uyumayı ertelememek (not postponing sleep) functions as the thing that is necessary.
Near-synonyms: gerek, gerekli, gerekir (slightly more formal or stronger).

Why is it uyumayı and not uyumak?

Because ertelemek (to postpone) is a transitive verb and takes a direct object. When a verb is turned into a noun to be the object of another verb, Turkish commonly uses the -mA nominalization plus the accusative:

uyu-ma-y-ı ertele- → “postpone sleeping.” So uyumayı is the object of ertelememek. Using bare uyumak as a direct object here is not idiomatic; -mAyI is the standard pattern.

What’s going on inside uyumayı morphologically?

uyu- (sleep) + -ma (verbal noun) → uyuma
buffer -y- (to prevent vowel clash)
accusative -ı (marks the direct object)
Result: uyumayı.

And how is ertelememek built?

ertele- (postpone) + -me- (negative) + -mek (infinitive/nominalizer with lazım)
Result: ertelememek = “not to postpone.”

Why is the negation on ertelememek instead of saying lazım değil?

Uyumayı ertelememek lazım = It is necessary not to postpone sleeping.
Uyumayı ertelemek lazım değil = It is not necessary to postpone sleeping (a weaker, different meaning).
They are not equivalent. Put the negation where the logic requires it. Avoid double negation like Uyumayı ertelememek lazım değil, which is confusing.

Could I say uyumayı ertelememeliyim / ertelememeliyiz / ertelemeyelim instead?

Yes, with different nuances:

Uyumayı ertelememeliyim = I shouldn’t postpone sleeping.
Uyumayı ertelememeliyiz = We shouldn’t postpone sleeping.
Uyumayı ertelemeyelim = Let’s not postpone sleeping.
… lazım is impersonal/general; -meli/-malı targets a specific subject or makes a more direct recommendation.

Is uyumayı ertelememek lazım natural? Are there alternatives?

It’s natural. Alternatives:

Uyumayı ertelemeyelim (more engaging: let’s not…).
Uyumayı geciktirmemek lazım (use geciktirmek = delay).
Uykuyu ertelememek lazım (use the noun uyku).
Uyumayı sonraya bırakmamak lazım (colloquial “not leave sleeping for later”).

Why does uyumayı take the accusative -ı? When would it not?

As the direct object of ertelemek, the verbal noun typically takes accusative (-ı/‑i/‑u/‑ü) to mark a specific, bounded action: uyumayı ertelemek.
You often see the accusative with -mA verbal nouns used as objects (e.g., sigara içmeyi bırak). Without accusative, the pattern is usually different (e.g., using -mak after certain verbs like istemek: uyumak istiyorum).

Could I just say Uyumak lazım?

Yes. Uyumak lazım = “It’s necessary to sleep / I should sleep.” Your sentence is more specific: it warns against the behavior of postponing sleep.

Is there any difference between using uyku (the noun) and uyumak (the verb) here?

Both are fine, with a nuance:

Uykuyu ertelememek lazım focuses on the noun “sleep.”
Uyumayı ertelememek lazım focuses on the act of sleeping.
Both are idiomatic; the second is slightly more action-oriented.

What are some natural connectors if I want to make the causal link explicit?

You can add:

Çünkü: Aniden esnedim, çünkü uyumayı ertelememek lazım. (I yawned suddenly because…)
Demek ki: Aniden esnedim; demek ki uyumayı ertelememek lazım. (So it seems we shouldn’t postpone sleep.)
The semicolon in your original already implies a related thought without an explicit connector.

Any quick synonyms I can swap in for style?

For aniden: birden, birdenbire, ansızın.
For ertelemek: geciktirmek, sonraya bırakmak, ötelemek (colloquial), tehir etmek (formal).
Pick based on register; all will keep the meaning clear.

What’s the typical word order here?

Default Turkish order places the finite verb at the end, but adverbs can come before the verb for emphasis:

(Ben) aniden esnedim; uyumayı ertelememek lazım.
Keeping each clause’s verb near the end sounds most natural.