All introverts can act extroverted for a while, just as right handed people can attempt to sign their name with their left hand. It just costs more energy for them to act that way. It's not impossible, but the preference is to limit that kind of activity.

If you have a look at your Cognitive functions, you'll see that all introverts have an auxiliary function that is extrovert. Developing that function (and the tertiary and inferior functions) helps introverts to cope.