You can say, for example, I was wondering if you would like to come to the cinema with me. It's not gramatically a question but nevertheless there is an expectation of an answer.
You could also say I was wondering: would you like to come to the cinema with me? which is definitely a question and which expalins what you were wondering about.
You can also use I was wondering in the past tense (imperfect). For example I was wondering if she wanted to come to the cinema with me when the telephone rang. In other words I was in the process of wondering about something when the telephone rang.