Learn Turkish: Hava çok sıcak, dondurma istiyorum. - The weather is very hot, I want ice cream.

In Turkish, you often do not need a word for 'is' when making a simple statement about the present. For 'I am' or 'you are', you add a personal suffix, but for 'he', 'she', or 'it' (like the weather), you just use the adjective alone. So, hava çok sıcak simply means 'the weather is very hot'.

Since 'ice cream' is the object I want, why isn't it dondurmayı?

You only use the accusative case ending (like -yı) when you are talking about a specific object, meaning 'the ice cream'. Because you are just saying you want ice cream in general, it stays in its basic dictionary form, dondurma.

The verb for 'to want' is istemek. Why is it istiyorum and not isteyorum?

When a verb root ends in a or e (like iste-), the continuous present tense suffix -yor changes that final vowel into ı, i, u, or ü to match vowel harmony. This is called vowel narrowing. Here, the e narrows to an i, making it istiyorum.

Do I need to say ben before istiyorum?