Can an abstract class have only method signatures without implementation like interfaces? is worded very poorly, and can mean a number of different things. Apparently, non-English or English-second-language speakers, or perhaps just poor English speakers, are unable to understand the question and are providing equally misleading answers.
I'm unable to edit any of it because I don't know the intent. Is this a vote to close? There's a reasonable question in there, but no one really knows what each other is talking about.