Hi Sinem. 1.In the second sentence you should say " I would really like it if you left me alone" because it's a second conditional ( if +simple past, would +infinitive). 2. I wonder if/whether she is married. You don't need to add "not" as the verb "wonder" already expresses doubt!

I will be very happy if you leave me alone. Incorrect I'd appreciate if you leave me alone Please leave me alone I wonder if she's married or not. Correct I wonder whether she's married or not. Correct

"I would really like it if you would leave me alone" is a very polite and perfect way to say this in any situation. The other option is grammatically correct, but not a very good option in most cases, as it sounds very rude. For example, the second sentence implies that the problem is not caused by the guest (e.g. you are busy, feeling sad, or feeling just a little irritated with life). The first sentence implies that the problem IS your guest. "I wonder if she's married or not" and "I wonder whether she's married or not" are completely equal and appropriate.