giggles and another annoying student episodes

I don't know if I'm a good teacher. Case in point: three girls had a case of the giggles on Friday afternoon in my 4pm class - ouch, right? Instead of sending them out in the hallway to get it together I gave them several warnings and then gave them a firmer reprimand after class. But any of the other teachers would have just sent them out. Instead I was trying to TEACH them English grammar and I don't think it stuck. Too often this is the case, (Frenchcoco tries to teach but fails pretty definitively) because I don't understand the French education culture here still, and I'm a big fat Newb to the profession. Also the fact that I waver too closely between being funny and likeable, and actually enforcing rules - the latter of which I think is actually more important as a teacher in France. There is much more of an open dialogue between students and teachers in the USA (especially in college) than in France, and by allowing or searching for that open dialogue in my classes with my students, it's led to a kind of misunderstanding in what my role is in the classroom. They're not used to it from their professors. And I'm not sure enough myself of what my role is to where I can reign them back in when they cross the line from being accessible to being inaccessibly lazy and indifferent. After the girls were reprimanded a third time, I lost my credibility for that afternoon class. I picked some of it back up after we spoke after class, but then tossed some of it to the wind when I spoke to them in French and incorrectly conjugated. No matter that they got the point of what I was saying and would hopefully do better next week, but I let MORE weakness show. A LION TAMER SHOWS NO WEAKNESS!! (see facebook post of what-teachers-do-pdf photo) I need to trade in my MeowMix for a bullwhip.