Cut them off right there

 Most Americans are good at talking continuously. If you don't interrupt them, they can go on and on and on. If you have something to say, but you are polite and don't want to interrupt them, you have to wait and wait. Sometimes they just switch to the next topic afterwards without stop, by then you feel like better to keep the current topic going without bringing the  "something" you had earlier. So this process repeats and you seat there waiting and waiting and says almost nothing at the end. This nice demeanor, however, leaves an impression of being passive and having not much to contribute. To remedy this situation, which can have a negative impact on most things you do in life (from career to making new friends), you have to learn to interrupt. Don't wait to say something. Say them right away as your ideas pop up. You don't need to ask for permission to ask a question. So cut them off and interrupt; being an interrupter gains you more respect. Actually Americans get to learn this in their lives too. So they wouldn't think you are rude if you are an interrupter because they are and expect you to interrupt.