Croatian: I don't know....
How do you say...

1. I don't know whether he gave her the hat.
2. I don't know when he gave her the hat.

Question

Croatian: I don't know....
How do you say...

1. I don't know whether he gave her the hat.
2. I don't know when he gave her the hat.

Answer

I don't know - ne znam 
whether - da li 
hat - šešir
1. Ne znam da li joj je dao šešir. 
When - kad (kada) , where - gdje, how - kako, who - tko
2. Ne znam kad joj dao šešir.

I hope this helps, if you have any questions more, feel free to ask me. 
Have a nice day.

Answer

1. Ne znam da li joj je dao klobuk/šešir.
2. Ne znam kada joj je dao šešir/klobuk.

Answer

Klobuk je stari izraz. Još uvijek je ponegdje u uporabi.