4. But as soon as that's done, you'll happily sit listening to the conversation without saying another word.
We are up to number 4 on the list of the 21 signs you might actually be an ambivert. The number 3 statement was about you as an ambivert talking for an extended period about something that you are passionate about.
Of course when that conversation has played itself out we, meaning us introverts and ambiverts will always slip back into type. That is we will listen to other people talking and bullshitting and will contribute a very minimal amount to the conversation if any amount.
I know from experience that I am very much like this. I will talk all night about rugby or cricket or something like that but when the conversation changes to something that I know not much about I won't even pretend that I am an expert and I don't say much .
Remember that you don't have to participate just because everyone else is. You may want to participate because you are a little afraid that other people might think you are being a little snooty. Well, my advice for you when that happens is to try not to worry about what other people MIGHT be thinking. That's their problem, not your problem.
In summary speak when you want to and don't feel that you have to when you are not sure about the topic. You will just come across at awkward.