"I am talking."
It's roughly like "talk" versus "speak" -- they can often be used interchangeably but sometimes one is preferred, e.g. we'd usually say "I can speak Spanish" (ich kann Spanisch sprechen) and "don't interrupt me when I'm talking" (unterbrich mich nicht, wenn ich rede), but it could be either in sentences such as "he's talking/speaking about his job" (er spricht/redet über seinen Job).
There is no continous form in German. The fact that you currently speak is not distinguishable from you speaking in general. To indicate that you are just doing something you can add "gerade" in German.
So in these cases you do not translate the "I am..." to "Ich bin..."
- I am sitting = Ich sitze (gerade).
- I am cooking = Ich koche (gerade)
German doesn't distinguish between when you are doing something right now and when you do something in general the way we do in English.
The sentences "I speak" and "I am speaking" would both be translated to "Ich spreche". "Ich bin spreche" is not a construction that is used in German.
On a "tap the pairs" question I had the following:
speak, are speaking sprecht, sprechen
Can someone please explain how to sort out which should be paired with which?
ihr sprecht, you are speaking ihr sprecht, you speak
wir sprechen, we are speaking wir sprechen, we speak
Both combinations should be accepted, but only one correct solution was accepted by Duolingo.