I can see how you might think that, and I can see many times where they can be. Namely is used when you want to give more detail or be more exact about something you have just said: We need to get more teachers into the classrooms where they're most needed, namely in high poverty areas. Specifically has two meanings: 1 for a particular reason, purpose, etc.: These jeans are designed specifically for women. 2 clearly, exactly, or in detail: I specifically asked you not to be late. In the first sentence I used 'namely' you can use 'specifically' there, and in really all cases you can replace 'namely' with 'specifically', but sometimes it sounds better with 'namely' since it's a shorter word. It's also better to use 'namely' when you have been talking about something and you want to give the exact information you've been hinting at or talking about. You can't use 'namely' without having talked about the topic before. It's like an interjection to get to the detail of what you've been saying. For some sentences where you use 'specifically' though it doesn't make sense to use 'namely', like the two sentences I used you wouldn't use 'namely' with these. Hopefully this is helpful.