Learn Hardcore Turkish: Gece hava çok soğuk olunca su donabilir. - When the weather is very cold at night, water can freeze.

olunca = ol- (to be/become) + -ınca/-ince/-unca/-ünce (when/once). Vowel harmony after o gives -unca. It introduces a time/condition: when/once it is/becomes.

Why use olunca instead of soğukken or soğuksa?

-ınca: when/once; often neutral time or mild cause.
-ken: while (simultaneous state), e.g., hava çok soğukken = while it’s very cold.
-sa/-se: if (conditional), e.g., hava çok soğuksa = if it’s very cold. Here, olunca gives a general when/whenever feeling that fits neutral statements.

Why do we need olmak here? Why not attach -ınca directly to soğuk?

-ınca attaches to verbs. soğuk is an adjective, so it uses the copular verb ol- to carry the suffix: soğuk olunca = when it is/becomes cold. Alternatives: soğukken (adjective + -ken) or çok soğuduğunda (verb soğumak + -dığında).

Does -ınca here mean when or since?

Primarily when/once. It can imply a mild causal sense (since/as) in some contexts, but with general truths like this, the temporal when/whenever reading is standard.

What does donabilir express, and how is it built?

Form: don- (freeze) + -(y)Abil (can/may) + aorist -(I)r → donabilir.
Meaning: possibility/ability — can/may freeze (not a definite or habitual claim).

How is donabilir different from donar, donuyor, and donacak?

donar: aorist/habitual — freezes (as a rule).
donuyor: present continuous — is freezing.
donacak: future — will freeze.
donabilir: modal possibility — may/can freeze.

Why is gece bare? Why not gecede?

Time words like gece, sabah, akşam often act as adverbs with no suffix: at night, in the morning, etc. gecede is possible but tends to mark a specific night/time; the bare form is the neutral choice here.

What’s the nuance between gece, geceleri, and geceleyin?

gece: at night (context can be specific or general).
geceleri: at nights/in the nighttime habitually (explicitly general).
geceleyin: at night (somewhat more formal/literary). All can work; geceleri foregrounds habit.

Does su mean the water or water in general? Why no article?

Turkish has no articles. Bare su here is generic: water (as a substance). For a specific referent, qualify it: borulardaki su (water in the pipes). Sular refers to multiple bodies/kinds of water, not the substance in general.

Can I change the word order, e.g., Su, gece hava çok soğuk olunca donabilir?

Yes. Turkish is flexible. Fronting su emphasizes it. The given order is neutral/informative. A comma after a long initial clause is optional for readability.

What does çok do, and where does it go?

çok intensifies: çok soğuk = very cold. It precedes the adjective. Omitting it softens the statement; alternatives include epey/oldukça (quite/fairly).

Pronunciation tips for soğuk and olunca?

ğ (in soğuk) lengthens/smooths the preceding vowel; it’s not a hard g: roughly so-uk with a long o.
c in olunca sounds like English j in jam: olunja. The u in -unca follows vowel harmony.

Could I use Hava çok soğuduğunda su donabilir instead? Any nuance?

Yes. soğuduğunda emphasizes the event/change of becoming cold. soğuk olunca presents a state being in effect. Both convey nearly the same idea here.

Does the verb agree with su? What if the subject is plural?

Yes. su is 3rd person singular, so donabilir is singular. With non-human plurals, the verb usually stays singular: Sular donabilir. A plural verb ending is optional mainly with specific human plural subjects.

Can you give a quick word-by-word gloss?

Gece — at night
hava — weather/air
çok — very
soğuk — cold
olunca — when/once it is/becomes (ol- + -ınca)
su — water
donabilir — can/may freeze (don- + -(y)Abil + -(I)r)