Öğleden sonra kaloriferi açtım, oda yavaşça ısındı.

In the afternoon I turned on the radiator, and the room slowly warmed up.

Breakdown of Öğleden sonra kaloriferi açtım, oda yavaşça ısındı.

• oda: the room
• ısınmak: to warm up
• öğleden sonra: in the afternoon
• yavaşça: slowly

Questions & Answers about Öğleden sonra kaloriferi açtım, oda yavaşça ısındı.

Why does it say kaloriferi with -i at the end?

The -i is the accusative case, used for definite direct objects. Kaloriferi açtım means you turned on a specific, known heating/radiator. Without -i (as in kalorifer açtım), it would be indefinite (“I turned on a radiator/heating”), which sounds odd here because your home’s heating is a specific thing.

Does açmak mean “open” or “turn on”?

Both. Açmak is “to open,” but for devices and utilities it also means “to turn on” (lights, TV, heating, water). So kaloriferi açtım is perfectly idiomatic for “I turned on the heating.”

What’s the exact form of açtım? Why not açdım?

It’s past tense, first person singular: stem aç- + past -DI + -m (I) → açtım. The D becomes T (consonant devoicing) after the voiceless consonant ç, so you get -t- rather than -d-.

Why is oda (room) in the bare form, not odada?

Because oda is the subject (“the room”). The nominative (bare form) marks subjects. Odada ısındı would mean “It warmed up in the room,” where “it” (not the room) is the subject.