Learn Turkish: Dolapta süt var. - There is milk in the cupboard.

Var is used to express that something exists, equivalent to 'there is' or 'there are' in English. Instead of starting the sentence with 'there is', Turkish puts var at the very end.

Why does the sentence start with dolapta (in the cupboard) instead of the milk?

In Turkish sentences expressing existence, the location usually comes first. The standard structure is almost always 'Location + Item + var'. So literally, it says 'In the cupboard milk exists.'

Why is the suffix for 'in' -ta here (dolapta) instead of the usual -da?

This is due to consonant harmony. Because the word dolap ends in a hard consonant (p), the d in the location suffix (-da) changes to a t to make it easier to pronounce, becoming -ta.

Can dolap also mean 'fridge'? Milk is usually kept in a fridge!

Yes! While dolap generally means cupboard, cabinet, or wardrobe, it is very commonly used as a short form for buzdolabı (refrigerator). Context tells us they probably mean the fridge here.