Learn Hardcore Turkish: İzolasyon olunca ev sıcak kalır. - When there is insulation, the house stays warm.

olunca is formed from the verb stem ol- (to be) plus the temporal/conditional suffix -unca (an allomorph of -ınca after o/u). It turns the clause into “when/once/if there is…”—in this case “When there is insulation…”.

Could I use olduğunda instead of olunca here?

Yes. olduğunda comes from ol- + a buffer consonant -d- + the suffix -ığında. It also means “when/once there is…” but is slightly more formal or explicit. You could say “İzolasyon olduğunda ev sıcak kalır,” though olunca is shorter and more colloquial.

Why do we say sıcak kalır instead of sıcak olur?

kalmak means “to remain” or “to stay.” So sıcak kalır literally means “stays warm.” If you used sıcak olur (becomes warm), it would imply a change to warmth rather than maintaining it.

What tense or aspect is conveyed by the -r in kalır?

The -r is the aorist (or simple present) suffix, used for general truths, habitual actions or states. Here it expresses a general fact: houses stay warm whenever they’re insulated.

Why is there no article before ev?

Turkish does not have definite or indefinite articles equivalent to the or a/an. Nouns like ev (house) appear in bare form; context or suffixes indicate specificity if needed.

What case is izolasyon in, and why doesn’t it take an ending?

izolasyon is in the nominative (unmarked) case because it functions as the subject of the subordinate olunca clause. In Turkish, only definite direct objects take the accusative ending (e.g. izolasyonu).

Can we change the word order or paraphrase this sentence?

Yes. Turkish has a flexible SOV structure. For example:
– Ev izolasyon olunca sıcak kalır.
– İzolasyon yapıldığında ev sıcak kalır.
You can also move the subordinate clause to the end:
– Ev sıcak kalır izolasyon olunca.
All convey the same general meaning.