Hello koss, 'Aren't I ?' is not a proper tag. It is used as a slang for "Am I not?". If you just used the sentence. " I am still part of the team." It is an affirmative sentence then,where you state and affirm being part of the team. Adding the question tag means you are not sure whether you are or not, you are uncertain and need an assuring answer to confirm,that you are still part of the team.

hi Koss according to my British friend, "aren't I" is not a slang because nowadays everyone uses it. it's too formal or old-fashioned to be considered as a "slang". the correct tag would be "am I not", but no one uses that. in my opinion, languages are living and changing, and they don't always follow the rules because people don't always follow the rules, either. :D hope this helps. :)

По-русски думаю понятнее будет =) Are\arent это everyday-speaking english.I`m более правильная грамматически. А в общем,такая форма называется то ли обратный вопрос, толи как,я точно не помню.Например: This picture is beautiful. Вопрос можно задать такой This picture is beautiful, isn`t it? Т.е. отрицание идет во второй части вопроса. Надеюсь понятно обьяснил